diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fde9f95..c6952b2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,16 +8,14 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - php: '7.4'
-            moodle-branch: 'master'
-            database: 'pgsql'
-          - php: '7.4'
-            moodle-branch: 'MOODLE_311_STABLE'
-            database: 'mariadb'
+          - { php: '8.1', moodle-branch: MOODLE_404_STABLE, database: pgsql }
+          - { php: '8.2', moodle-branch: MOODLE_405_STABLE, database: mariadb }
+          - { php: '8.3', moodle-branch: MOODLE_500_STABLE, database: pgsql }
+          - { php: '8.3', moodle-branch: main, database: pgsql }
 
     services:
       postgres:
-        image: postgres
+        image: postgres:14
         env:
           POSTGRES_USER: 'postgres'
           POSTGRES_HOST_AUTH_METHOD: 'trust'
@@ -30,7 +28,7 @@ jobs:
           - 5432:5432
 
       mariadb:
-        image: mariadb
+        image: mariadb:10
         env:
           MYSQL_USER: 'root'
           MYSQL_ALLOW_EMPTY_PASSWORD: "true"
@@ -49,25 +47,25 @@ jobs:
         with:
           node-version: '14.15.0'
 
-      - name: Setup PHP
+      - name: Setup PHP ${{ matrix.php }}
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          extensions: mbstring, pgsql, mysqli
-#          tools: phpunit
-#          coverage: none
+          extensions: ${{ matrix.extensions }}
+          ini-values: max_input_vars=5000
+          coverage: none
 
-      - name: Deploy moodle-plugin-ci
+      - name: Initialise moodle-plugin-ci
         run: |
-          composer create-project -n --no-dev --prefer-dist moodlehq/moodle-plugin-ci ci ^3
-          # Add dirs to $PATH
+          composer create-project -n --no-dev --prefer-dist moodlehq/moodle-plugin-ci ci ^4
           echo $(cd ci/bin; pwd) >> $GITHUB_PATH
           echo $(cd ci/vendor/bin; pwd) >> $GITHUB_PATH
-          # PHPUnit depends on en_AU.UTF-8 locale
           sudo locale-gen en_AU.UTF-8
+          echo "NVM_DIR=$HOME/.nvm" >> $GITHUB_ENV
 
-      - name: Install Moodle
-        run: moodle-plugin-ci install --plugin ./plugin --db-host=127.0.0.1
+      - name: Install moodle-plugin-ci
+        run: |
+          moodle-plugin-ci install --plugin ./plugin --db-host=127.0.0.1
         env:
           DB: ${{ matrix.database }}
           MOODLE_BRANCH: ${{ matrix.moodle-branch }}
diff --git a/backup/moodle2/backup_qtype_oumultiresponse_plugin.class.php b/backup/moodle2/backup_qtype_oumultiresponse_plugin.class.php
index bfa6d8d..2dc21e5 100644
--- a/backup/moodle2/backup_qtype_oumultiresponse_plugin.class.php
+++ b/backup/moodle2/backup_qtype_oumultiresponse_plugin.class.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Backup plugin for the OU multiple response question type.
+ *
  * @package    qtype_oumultiresponse
  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -47,18 +49,19 @@ protected function define_question_plugin_structure() {
         $this->add_question_question_answers($pluginwrapper);
 
         // Now create the qtype own structures.
-        $oumultiresponse = new backup_nested_element('oumultiresponse', array('id'), array(
+        $oumultiresponse = new backup_nested_element('oumultiresponse', ['id'], [
             'shuffleanswers', 'correctfeedback', 'correctfeedbackformat',
             'partiallycorrectfeedback', 'partiallycorrectfeedbackformat',
             'incorrectfeedback', 'incorrectfeedbackformat', 'answernumbering',
-            'shownumcorrect', 'showstandardinstruction'));
+            'shownumcorrect', 'showstandardinstruction',
+        ]);
 
         // Now the own qtype tree.
         $pluginwrapper->add_child($oumultiresponse);
 
         // Set source to populate the data.
         $oumultiresponse->set_source_table('question_oumultiresponse',
-                array('questionid' => backup::VAR_PARENTID));
+            ['questionid' => backup::VAR_PARENTID]);
 
         // Don't need to annotate ids nor files.
 
@@ -72,9 +75,10 @@ protected function define_question_plugin_structure() {
      * files to be processed both in backup and restore.
      */
     public static function get_qtype_fileareas() {
-        return array(
+        return [
             'correctfeedback' => 'question_created',
             'partiallycorrectfeedback' => 'question_created',
-            'incorrectfeedback' => 'question_created');
+            'incorrectfeedback' => 'question_created',
+        ];
     }
 }
diff --git a/backup/moodle2/restore_qtype_oumultiresponse_plugin.class.php b/backup/moodle2/restore_qtype_oumultiresponse_plugin.class.php
index 586f513..0b0fcb9 100644
--- a/backup/moodle2/restore_qtype_oumultiresponse_plugin.class.php
+++ b/backup/moodle2/restore_qtype_oumultiresponse_plugin.class.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Restore plugin class for the OU multiple response question type.
+ *
  * @package    qtype_oumultiresponse
  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -34,7 +36,7 @@ class restore_qtype_oumultiresponse_plugin extends restore_qtype_plugin {
      */
     protected function define_question_plugin_structure() {
 
-        $paths = array();
+        $paths = [];
 
         // This qtype uses question_answers, add them.
         $this->add_question_question_answers($paths);
@@ -74,6 +76,7 @@ public function process_oumultiresponse($data) {
         }
     }
 
+    #[\Override]
     public function recode_response($questionid, $sequencenumber, array $response) {
         if (array_key_exists('_order', $response)) {
             $response['_order'] = $this->recode_choice_order($response['_order']);
@@ -87,7 +90,7 @@ public function recode_response($questionid, $sequencenumber, array $response) {
      * @return string the recoded order.
      */
     protected function recode_choice_order($order) {
-        $neworder = array();
+        $neworder = [];
         foreach (explode(',', $order) as $id) {
             if ($newid = $this->get_mappingid('question_answer', $id)) {
                 $neworder[] = $newid;
@@ -101,9 +104,9 @@ protected function recode_choice_order($order) {
      */
     public static function define_decode_contents() {
 
-        $contents = array();
+        $contents = [];
 
-        $fields = array('correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback');
+        $fields = ['correctfeedback', 'partiallycorrectfeedback', 'incorrectfeedback'];
         $contents[] = new restore_decode_content('question_oumultiresponse',
                 $fields, 'question_oumultiresponse');
 
diff --git a/changes.md b/changes.md
index 0f1530d..cfa01e7 100644
--- a/changes.md
+++ b/changes.md
@@ -1,5 +1,15 @@
 # Change log for the OU Multi-response question type
 
+## Changes in 2.5
+* This version works with Moodle 5.0.
+* Automation test failures are fixed.
+* Cherry-picked commits since february 2024 till now:
+  * Update btn to "Save preview options and start again"
+  * Fix backup and restore tests to run synchronously M4.4
+  * Choice Tiny Editor disrupts the theme column layout on edit question page
+  * Add required for answer field when user not submit an answer
+* Upgrade the CI to support Moodle 5.0 (PHP 8.3), and update the branch to support branch MOODLE_405_STABLE, and MOODLE_500_STABLE.
+
 ## Changes in 2.4
 
 * This version works with Moodle 4.0.
diff --git a/classes/output/mobile.php b/classes/output/mobile.php
index bd28671..0faa57e 100644
--- a/classes/output/mobile.php
+++ b/classes/output/mobile.php
@@ -25,6 +25,9 @@
  */
 class mobile {
 
+    /**
+     * Returns the mobile output for the oumultiresponse question type.
+     */
     public static function oumr_view() {
         global $CFG;
         // General notes:
@@ -35,9 +38,9 @@ public static function oumr_view() {
         return [
             'templates' => [[
                 'id' => 'main',
-                'html' => file_get_contents($CFG->dirroot . '/question/type/oumultiresponse/mobile/oumr.html')
+                'html' => file_get_contents($CFG->dirroot . '/question/type/oumultiresponse/mobile/oumr.html'),
             ]],
-            'javascript' => file_get_contents($CFG->dirroot . '/question/type/oumultiresponse/mobile/oumr.js')
+            'javascript' => file_get_contents($CFG->dirroot . '/question/type/oumultiresponse/mobile/oumr.js'),
         ];
     }
 }
diff --git a/classes/privacy/provider.php b/classes/privacy/provider.php
index 3a8b0ed..ad8e578 100644
--- a/classes/privacy/provider.php
+++ b/classes/privacy/provider.php
@@ -13,6 +13,7 @@
 //
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
 /**
  * Privacy Subsystem implementation for qtype_oumultiresponse.
  *
@@ -22,10 +23,10 @@
  */
 namespace qtype_oumultiresponse\privacy;
 
-use \core_privacy\local\metadata\collection;
-use \core_privacy\local\request\transform;
-use \core_privacy\local\request\user_preference_provider;
-use \core_privacy\local\request\writer;
+use core_privacy\local\metadata\collection;
+use core_privacy\local\request\transform;
+use core_privacy\local\request\user_preference_provider;
+use core_privacy\local\request\writer;
 
 /**
  * Privacy Subsystem for qtype_oumultiresponse implementing user_preference_provider.
diff --git a/classes/utils.php b/classes/utils.php
new file mode 100644
index 0000000..fdb66af
--- /dev/null
+++ b/classes/utils.php
@@ -0,0 +1,104 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Utility functions for the oumultiresponse question type.
+ *
+ * @package qtype_oumultiresponse
+ * @copyright 2025 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace qtype_oumultiresponse;
+
+/**
+ * Class that holds utility functions used by the oumultiresponse question type.
+ *
+ * @package qtype_oumultiresponse
+ * @copyright 2025 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class utils {
+
+    /** @var string - Less than operator */
+    const OP_LT = "<";
+    /** @var string - equal operator */
+    const OP_E = "=";
+    /** @var string - greater than operator */
+    const OP_GT = ">";
+
+    /**
+     * Conveniently compare the current moodle version to a provided version in branch format. This function will
+     * inflate version numbers to a three digit number before comparing them. This way moodle minor versions greater
+     * than 9 can be correctly and easily compared.
+     *
+     * Examples:
+     *   utils::moodle_version_is("<", "39");
+     *   utils::moodle_version_is("<=", "310");
+     *   utils::moodle_version_is(">", "39");
+     *   utils::moodle_version_is(">=", "38");
+     *   utils::moodle_version_is("=", "41");
+     *
+     * CFG reference:
+     * $CFG->branch = "311", "310", "39", "38", ...
+     * $CFG->release = "3.11+ (Build: 20210604)", ...
+     * $CFG->version = "2021051700.04", ...
+     *
+     * @param string $operator for the comparison
+     * @param string $version to compare to
+     * @return boolean
+     */
+    public static function moodle_version_is(string $operator, string $version): bool {
+        global $CFG;
+
+        if (strlen($version) == 2) {
+            $version = $version[0]."0".$version[1];
+        }
+
+        $current = $CFG->branch;
+        if (strlen($current) == 2) {
+            $current = $current[0]."0".$current[1];
+        }
+
+        $from = intval($current);
+        $to = intval($version);
+        $ops = str_split($operator);
+
+        foreach ($ops as $op) {
+            switch ($op) {
+                case self::OP_LT:
+                    if ($from < $to) {
+                        return true;
+                    }
+                    break;
+                case self::OP_E:
+                    if ($from == $to) {
+                        return true;
+                    }
+                    break;
+                case self::OP_GT:
+                    if ($from > $to) {
+                        return true;
+                    }
+                    break;
+                default:
+                    throw new \coding_exception('invalid operator '.$op);
+            }
+        }
+
+        return false;
+    }
+}
diff --git a/combinable/combinable.php b/combinable/combinable.php
index 7c872ec..5630109 100644
--- a/combinable/combinable.php
+++ b/combinable/combinable.php
@@ -25,18 +25,29 @@
 
 defined('MOODLE_INTERNAL') || die();
 
+/**
+ * Combined question type for oumultiresponse.
+ */
 class qtype_combined_combinable_type_oumultiresponse extends qtype_combined_combinable_type_base {
 
+    /**
+     * The question type identifier.
+     *
+     * @var string
+     */
     protected $identifier = 'multiresponse';
 
+    #[\Override]
     protected function extra_question_properties() {
         return $this->combined_feedback_properties();
     }
 
+    #[\Override]
     protected function extra_answer_properties() {
-        return array('feedback' => array('text' => '', 'format' => FORMAT_PLAIN));
+        return ['feedback' => ['text' => '', 'format' => FORMAT_PLAIN]];
     }
 
+    #[\Override]
     public function subq_form_fragment_question_option_fields() {
         return [
             'shuffleanswers' => (bool) get_config('qtype_combined', 'shuffleanswers_multiresponse'),
@@ -44,26 +55,27 @@ public function subq_form_fragment_question_option_fields() {
         ];
     }
 
+    #[\Override]
     protected function transform_subq_form_data_to_full($subqdata) {
         $data = parent::transform_subq_form_data_to_full($subqdata);
         foreach ($data->answer as $anskey => $answer) {
-            $data->answer[$anskey] = array('text' => $answer['text'], 'format' => $answer['format']);
+            $data->answer[$anskey] = ['text' => $answer['text'], 'format' => $answer['format']];
         }
         return $this->add_per_answer_properties($data);
     }
 
+    #[\Override]
     protected function third_param_for_default_question_text() {
         return 'v';
     }
 }
 
+/**
+ * Class question type for combined combinable oumultiresponse.
+ */
 class qtype_combined_combinable_oumultiresponse extends qtype_combined_combinable_accepts_vertical_or_horizontal_layout_param {
 
-    /**
-     * @param moodleform      $combinedform
-     * @param MoodleQuickForm $mform
-     * @param                 $repeatenabled
-     */
+    #[\Override]
     public function add_form_fragment(moodleform $combinedform, MoodleQuickForm $mform, $repeatenabled) {
         $mform->addElement('advcheckbox', $this->form_field_name('shuffleanswers'),
             get_string('shuffle', 'qtype_combined'));
@@ -75,12 +87,12 @@ public function add_form_fragment(moodleform $combinedform, MoodleQuickForm $mfo
         $mform->setDefault($this->form_field_name('answernumbering'),
                 get_config('qtype_combined', 'answernumbering_multiresponse'));
 
-        $answerels = array();
+        $answerels = [];
         $answerels[] = $mform->createElement('editor', $this->form_field_name('answer'),
                 get_string('choiceno', 'qtype_multichoice', '{no}'), ['rows' => 2]);
         $mform->setType($this->form_field_name('answer'), PARAM_RAW);
         $answerels[] = $mform->createElement('advcheckbox', $this->form_field_name('correctanswer'),
-                get_string('correct', 'question'), get_string('correct', 'question'));
+                '', get_string('correct', 'question'));
 
         $answergroupel = $mform->createElement('group',
                 $this->form_field_name('answergroup'),
@@ -93,9 +105,9 @@ public function add_form_fragment(moodleform $combinedform, MoodleQuickForm $mfo
             $repeatsatstart = max(5, QUESTION_NUMANS_START);
         }
 
-        $combinedform->repeat_elements(array($answergroupel),
+        $combinedform->repeat_elements([$answergroupel],
             $repeatsatstart,
-            array(),
+            [],
             $this->form_field_name('noofchoices'),
             $this->form_field_name('morechoices'),
             QUESTION_NUMANS_ADD,
@@ -103,8 +115,9 @@ public function add_form_fragment(moodleform $combinedform, MoodleQuickForm $mfo
             true);
     }
 
+    #[\Override]
     public function data_to_form($context, $fileoptions) {
-        $mroptions = array('answer' => array(), 'correctanswer' => array());
+        $mroptions = ['answer' => [], 'correctanswer' => []];
         if ($this->questionrec !== null) {
             foreach ($this->questionrec->options->answers as $questionrecanswer) {
                 $mroptions['answer'][] = [
@@ -117,9 +130,10 @@ public function data_to_form($context, $fileoptions) {
         return parent::data_to_form($context, $fileoptions) + $mroptions;
     }
 
+    #[\Override]
     public function validate() {
-        $errors = array();
-        $nonemptyanswerblanks = array();
+        $errors = [];
+        $nonemptyanswerblanks = [];
         foreach ($this->formdata->answer as $anskey => $answer) {
             $answer = $answer['text'];
             if ('' !== trim($answer)) {
@@ -138,6 +152,7 @@ public function validate() {
         return $errors;
     }
 
+    #[\Override]
     public function has_submitted_data() {
         return $this->submitted_data_array_not_empty('correctanswer') ||
                 $this->html_field_has_submitted_data($this->form_field_name('answer')) ||
diff --git a/combinable/renderer.php b/combinable/renderer.php
index 6a07327..4a4f0d5 100644
--- a/combinable/renderer.php
+++ b/combinable/renderer.php
@@ -22,10 +22,10 @@
  * @author     Jamie Pratt <me@jamiep.org>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
-
 class qtype_oumultiresponse_embedded_renderer extends qtype_renderer
     implements qtype_combined_subquestion_renderer_interface {
 
+    #[\Override]
     public function subquestion(question_attempt $qa,
                                 question_display_options $options,
                                 qtype_combined_combinable_base $subq,
@@ -34,21 +34,22 @@ public function subquestion(question_attempt $qa,
         $fullresponse = new qtype_combined_response_array_param($qa->get_last_qt_data());
         $response = $fullresponse->for_subq($subq);
 
-        $commonattributes = array(
-            'type' => 'checkbox'
-        );
+        $commonattributes = [
+            'type' => 'checkbox',
+            'class' => empty($response) ? 'required' : '',
+        ];
 
         if ($options->readonly) {
             $commonattributes['disabled'] = 'disabled';
         }
 
-        $checkboxes = array();
-        $feedbackimg = array();
-        $classes = array();
+        $checkboxes = [];
+        $feedbackimg = [];
+        $classes = [];
         foreach ($question->get_order($qa) as $value => $ansid) {
             $inputname = $qa->get_qt_field_name($subq->step_data_name('choice'.$value));
             $ans = $question->answers[$ansid];
-            $inputattributes = array();
+            $inputattributes = [];
             $inputattributes['name'] = $inputname;
             $inputattributes['value'] = 1;
             $inputattributes['id'] = $inputname;
@@ -59,11 +60,11 @@ public function subquestion(question_attempt $qa,
             }
             $hidden = '';
             if (!$options->readonly) {
-                $hidden = html_writer::empty_tag('input', array(
+                $hidden = html_writer::empty_tag('input', [
                     'type' => 'hidden',
                     'name' => $inputattributes['name'],
                     'value' => 0,
-                ));
+                ]);
             }
 
             $choice = html_writer::div($question->format_text($ans->answer, $ans->answerformat, $qa,
@@ -95,10 +96,10 @@ public function subquestion(question_attempt $qa,
 
         foreach ($checkboxes as $key => $checkbox) {
             $cbhtml .= html_writer::tag($inputwraptag, $checkbox . ' ' . $feedbackimg[$key],
-                                        array('class' => $classes[$key])) . "\n";
+                ['class' => $classes[$key]]) . "\n";
         }
 
-        $result = html_writer::tag($inputwraptag, $cbhtml, array('class' => 'answer'));
+        $result = html_writer::tag($inputwraptag, $cbhtml, ['class' => 'answer']);
         $result = html_writer::div($result, $classname);
 
         // Load JS module for the question answers.
diff --git a/db/mobile.php b/db/mobile.php
index 543e557..950a032 100644
--- a/db/mobile.php
+++ b/db/mobile.php
@@ -29,8 +29,8 @@
         'handlers' => [
             'oumultiresponse' => [
                 'delegate' => 'CoreQuestionDelegate',
-                'method' => 'oumr_view'
-            ]
-        ]
-    ]
+                'method' => 'oumr_view',
+            ],
+        ],
+    ],
 ];
diff --git a/edit_oumultiresponse_form.php b/edit_oumultiresponse_form.php
index f32ef8b..875f26c 100644
--- a/edit_oumultiresponse_form.php
+++ b/edit_oumultiresponse_form.php
@@ -30,6 +30,7 @@
  */
 class qtype_oumultiresponse_edit_form extends question_edit_form {
 
+    #[\Override]
     protected function definition_inner($mform) {
         $mform->addElement('advcheckbox', 'shuffleanswers',
                 get_string('shuffleanswers', 'qtype_multichoice'), null, null, [0, 1]);
@@ -57,9 +58,10 @@ protected function definition_inner($mform) {
         $this->add_interactive_settings(true, true);
     }
 
+    #[\Override]
     protected function get_per_answer_fields($mform, $label, $gradeoptions,
             &$repeatedoptions, &$answersoption) {
-        $repeated = array();
+        $repeated = [];
         $repeated[] = $mform->createElement('editor', 'answer',
                 $label, ['rows' => 2], $this->editoroptions);
         $repeated[] = $mform->createElement('checkbox', 'correctanswer',
@@ -74,6 +76,7 @@ protected function get_per_answer_fields($mform, $label, $gradeoptions,
         return $repeated;
     }
 
+    #[\Override]
     protected function get_hint_fields($withclearwrong = false, $withshownumpartscorrect = false) {
         list($repeated, $repeatedoptions) = parent::get_hint_fields(
                 $withclearwrong, $withshownumpartscorrect);
@@ -95,9 +98,10 @@ protected function get_hint_fields($withclearwrong = false, $withshownumpartscor
             $repeated[] = $showchoicefeedback;
         }
 
-        return array($repeated, $repeatedoptions);
+        return [$repeated, $repeatedoptions];
     }
 
+    #[\Override]
     protected function data_preprocessing($question) {
         $question = parent::data_preprocessing($question);
         $question = $this->data_preprocessing_answers($question, true);
@@ -129,6 +133,7 @@ protected function data_preprocessing($question) {
         return $question;
     }
 
+    #[\Override]
     public function validation($data, $files) {
         $errors = parent::validation($data, $files);
 
@@ -163,6 +168,11 @@ public function validation($data, $files) {
         return $errors;
     }
 
+    /**
+     * Returns the question type.
+     *
+     * @return string The question type.
+     */
     public function qtype() {
         return 'oumultiresponse';
     }
diff --git a/lang/en/qtype_oumultiresponse.php b/lang/en/qtype_oumultiresponse.php
index 799af2f..86ccc17 100644
--- a/lang/en/qtype_oumultiresponse.php
+++ b/lang/en/qtype_oumultiresponse.php
@@ -37,14 +37,14 @@
 $string['pluginnamesummary'] = '<p>A multiple-choice, multiple-response question type with particular scoring rules.</p>
 <p>Recommended if your question has more than one correct answer.</p>';
 $string['privacy:metadata'] = 'Multiple response question type plugin allows question authors to set default options as user preferences.';
+$string['privacy:preference:answernumbering'] = 'Which numbering stye should be used (1., 2., 3., .../a., b., c., ... etc.)';
 $string['privacy:preference:defaultmark'] = 'The default mark set for a given question.';
 $string['privacy:preference:penalty'] = 'The penalty for each incorrect try when questions are run using the \'Interactive with multiple tries\' or \'Adaptive mode\' behaviour.';
-$string['privacy:preference:shuffleanswers'] = 'Whether the answers should be automatically shuffled.';
-$string['privacy:preference:answernumbering'] = 'Which numbering stye should be used (1., 2., 3., .../a., b., c., ... etc.)';
 $string['privacy:preference:showstandardinstruction'] = 'Whether showing standard instruction.';
-$string['toomanyoptions'] = 'You have selected too many options.';
+$string['privacy:preference:shuffleanswers'] = 'Whether the answers should be automatically shuffled.';
 $string['showeachanswerfeedback'] = 'Show the feedback for the selected responses.';
-$string['yougotnright'] = 'You have correctly selected {$a->num} options.';
-$string['yougot1right'] = 'You have correctly selected one option.';
 $string['showstandardinstruction'] = 'Show standard instruction';
 $string['showstandardinstruction_help'] = 'With this setting enabled, standard instruction will be supplied as part of the selection area (e.g. "Select one or more:"). If disabled, question authors can instead included instructions in the question content, if required.';
+$string['toomanyoptions'] = 'You have selected too many options.';
+$string['yougot1right'] = 'You have correctly selected one option.';
+$string['yougotnright'] = 'You have correctly selected {$a->num} options.';
diff --git a/lib.php b/lib.php
index a9adc7a..bbbdded 100644
--- a/lib.php
+++ b/lib.php
@@ -25,7 +25,7 @@
 /**
  * Checks file access for oumultiresponse questions.
  */
-function qtype_oumultiresponse_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options = array()) {
+function qtype_oumultiresponse_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options = []) {
     global $CFG;
     require_once($CFG->libdir . '/questionlib.php');
     question_pluginfile($course, $context, 'qtype_oumultiresponse', $filearea, $args, $forcedownload, $options);
diff --git a/question.php b/question.php
index e9dc0aa..385dc4d 100644
--- a/question.php
+++ b/question.php
@@ -52,6 +52,7 @@ public function get_renderer(moodle_page $page) {
         return $page->get_renderer('qtype_oumultiresponse');
     }
 
+    #[\Override]
     public function make_behaviour(question_attempt $qa, $preferredbehaviour) {
         if ($preferredbehaviour == 'interactive') {
             return question_engine::make_behaviour(
@@ -60,6 +61,7 @@ public function make_behaviour(question_attempt $qa, $preferredbehaviour) {
         return question_engine::make_archetypal_behaviour($preferredbehaviour, $qa);
     }
 
+    #[\Override]
     public function classify_response(array $response) {
         $choices = parent::classify_response($response);
         $numright = $this->get_num_correct_choices();
@@ -69,6 +71,9 @@ public function classify_response(array $response) {
         return $choices;
     }
 
+    /**
+     * Grade the response.
+     */
     public function grade_response(array $response) {
         list($numright, $total) = $this->get_num_parts_right($response);
         $numwrong = $this->get_num_selected_choices($response) - $numright;
@@ -81,17 +86,21 @@ public function grade_response(array $response) {
             $state = question_state::$gradedpartial;
         }
 
-        return array($fraction, $state);
+        return [$fraction, $state];
     }
 
+    #[\Override]
     protected function disable_hint_settings_when_too_many_selected(
             question_hint_with_parts $hint) {
         parent::disable_hint_settings_when_too_many_selected($hint);
         $hint->showchoicefeedback = false;
     }
 
+    /**
+     * Compute the final grade.
+     */
     public function compute_final_grade($responses, $totaltries) {
-        $responsehistories = array();
+        $responsehistories = [];
         foreach ($this->order as $key => $ansid) {
             $fieldname = $this->field($key);
             $responsehistories[$ansid] = '';
@@ -123,7 +132,7 @@ public static function grade_computation($responsehistory, $answers,
             $penalty, $questionnumtries) {
         // First we reverse the strings to get the most recent responses to the start, then
         // distinguish right and wrong by replacing 1 with 2 for right answers.
-        $workspace = array();
+        $workspace = [];
         $numright = 0;
         foreach ($responsehistory as $id => $string) {
             $workspace[$id] = strrev($string);
@@ -151,7 +160,7 @@ public static function grade_computation($responsehistory, $answers,
             }
             if ($numselected > $numright) {
                 $numtoclear = $numselected - $numright;
-                $newworkspace = array();
+                $newworkspace = [];
                 foreach ($workspace as $string) {
                     if (substr($string, $try, 1) == '2' && $numtoclear > 0) {
                         $string = self::replace_char_at($string, $try, '0');
@@ -183,6 +192,13 @@ public static function grade_computation($responsehistory, $answers,
         return array_sum($scores);
     }
 
+    /**
+     * Replace a character at a given position.
+     *
+     * @param string $string The string to modify.
+     * @param int $pos The position of the character to replace (0-based).
+     * @param string $newchar The new character to insert.
+     */
     public static function replace_char_at($string, $pos, $newchar) {
         return substr($string, 0, $pos) . $newchar . substr($string, $pos + 1);
     }
diff --git a/questiontype.php b/questiontype.php
index 5f76bef..42380ac 100644
--- a/questiontype.php
+++ b/questiontype.php
@@ -43,21 +43,28 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class qtype_oumultiresponse extends question_type {
+
+    #[\Override]
     public function has_html_answers() {
         return true;
     }
 
+    /**
+     * Get the name of this question type.
+     */
     public function requires_qtypes() {
-        return array('multichoice');
+        return ['multichoice'];
     }
 
+    #[\Override]
     public function get_question_options($question) {
         global $DB;
         $question->options = $DB->get_record('question_oumultiresponse',
-                array('questionid' => $question->id), '*', MUST_EXIST);
+            ['questionid' => $question->id], '*', MUST_EXIST);
         parent::get_question_options($question);
     }
 
+    #[\Override]
     public function save_defaults_for_new_questions(stdClass $fromform): void {
         parent::save_defaults_for_new_questions($fromform);
         $this->set_default_value('shuffleanswers', $fromform->shuffleanswers);
@@ -65,13 +72,14 @@ public function save_defaults_for_new_questions(stdClass $fromform): void {
         $this->set_default_value('showstandardinstruction', $fromform->showstandardinstruction);
     }
 
+    #[\Override]
     public function save_question_options($question) {
         global $DB;
         $context = $question->context;
         $result = new stdClass();
 
         $oldanswers = $DB->get_records('question_answers',
-                array('question' => $question->id), 'id ASC');
+            ['question' => $question->id], 'id ASC');
 
         // The following hack to checks that at least two answers exist.
         $answercount = 0;
@@ -86,7 +94,7 @@ public function save_question_options($question) {
         }
 
         // Insert all the new answers.
-        $answers = array();
+        $answers = [];
         foreach ($question->answer as $key => $answerdata) {
             if (trim($answerdata['text']) == '') {
                 continue;
@@ -118,11 +126,11 @@ public function save_question_options($question) {
         $fs = get_file_storage();
         foreach ($oldanswers as $oldanswer) {
             $fs->delete_area_files($context->id, 'question', 'answerfeedback', $oldanswer->id);
-            $DB->delete_records('question_answers', array('id' => $oldanswer->id));
+            $DB->delete_records('question_answers', ['id' => $oldanswer->id]);
         }
 
         $options = $DB->get_record('question_oumultiresponse',
-                array('questionid' => $question->id));
+            ['questionid' => $question->id]);
         if (!$options) {
             $options = new stdClass();
             $options->questionid = $question->id;
@@ -142,12 +150,13 @@ public function save_question_options($question) {
         $this->save_hints($question, true);
     }
 
+    #[\Override]
     public function save_hints($formdata, $withparts = false) {
         global $DB;
         $context = $formdata->context;
 
         $oldhints = $DB->get_records('question_hints',
-                array('questionid' => $formdata->id), 'id ASC');
+            ['questionid' => $formdata->id], 'id ASC');
 
         if (!empty($formdata->hint)) {
             $numhints = max(array_keys($formdata->hint)) + 1;
@@ -217,20 +226,23 @@ public function save_hints($formdata, $withparts = false) {
         $fs = get_file_storage();
         foreach ($oldhints as $oldhint) {
             $fs->delete_area_files($context->id, 'question', 'hint', $oldhint->id);
-            $DB->delete_records('question_hints', array('id' => $oldhint->id));
+            $DB->delete_records('question_hints', ['id' => $oldhint->id]);
         }
     }
 
+    #[\Override]
     protected function make_hint($hint) {
         return qtype_oumultiresponse_hint::load_from_record($hint);
     }
 
+    #[\Override]
     // phpcs:ignore Generic.CodeAnalysis.UselessOverridingMethod.Found
     public function make_answer($answer) {
         // Overridden just so we can make it public for use by question.php.
         return parent::make_answer($answer);
     }
 
+    #[\Override]
     protected function initialise_question_instance(question_definition $question, $questiondata) {
         parent::initialise_question_instance($question, $questiondata);
         $question->shuffleanswers = $questiondata->options->shuffleanswers;
@@ -240,12 +252,18 @@ protected function initialise_question_instance(question_definition $question, $
         $this->initialise_question_answers($question, $questiondata, false);
     }
 
+    #[\Override]
     public function delete_question($questionid, $contextid) {
         global $DB;
-        $DB->delete_records('question_oumultiresponse', array('questionid' => $questionid));
+        $DB->delete_records('question_oumultiresponse', ['questionid' => $questionid]);
         return parent::delete_question($questionid, $contextid);
     }
 
+    /**
+     * Get the number of correct choices in the question.
+     *
+     * @param question_definition $questiondata The question data.
+     */
     protected function get_num_correct_choices($questiondata) {
         $numright = 0;
         foreach ($questiondata->options->answers as $answer) {
@@ -256,6 +274,7 @@ protected function get_num_correct_choices($questiondata) {
         return $numright;
     }
 
+    #[\Override]
     public function get_random_guess_score($questiondata) {
         // We compute the randome guess score here on the assumption we are using
         // the deferred feedback behaviour, and the question text tells the
@@ -266,18 +285,20 @@ public function get_random_guess_score($questiondata) {
                 count($questiondata->options->answers);
     }
 
+    #[\Override]
     public function get_possible_responses($questiondata) {
         $numright = $this->get_num_correct_choices($questiondata);
-        $parts = array();
+        $parts = [];
 
         foreach ($questiondata->options->answers as $aid => $answer) {
-            $parts[$aid] = array($aid =>
-                    new question_possible_response($answer->answer, $answer->fraction / $numright));
+            $parts[$aid] = [$aid =>
+                new question_possible_response($answer->answer, $answer->fraction / $numright)];
         }
 
         return $parts;
     }
 
+    #[\Override]
     public function import_from_xml($data, $question, qformat_xml $format, $extra=null) {
         if (!isset($data['@']['type']) || $data['@']['type'] != 'oumultiresponse') {
             return false;
@@ -287,11 +308,11 @@ public function import_from_xml($data, $question, qformat_xml $format, $extra=nu
         $question->qtype = 'oumultiresponse';
 
         $question->shuffleanswers = $format->trans_single(
-                $format->getpath($data, array('#', 'shuffleanswers', 0, '#'), 1));
+            $format->getpath($data, ['#', 'shuffleanswers', 0, '#'], 1));
         $question->answernumbering = $format->getpath($data,
-                array('#', 'answernumbering', 0, '#'), 'abc');
+            ['#', 'answernumbering', 0, '#'], 'abc');
         $question->showstandardinstruction = $format->getpath($data,
-            array('#', 'showstandardinstruction', 0, '#'), 1);
+            ['#', 'showstandardinstruction', 0, '#'], 1);
 
         $format->import_combined_feedback($question, $data, true);
 
@@ -308,7 +329,7 @@ public function import_from_xml($data, $question, qformat_xml $format, $extra=nu
             if (array_key_exists('correctanswer', $answer['#'])) {
                 $keys = array_keys($question->correctanswer);
                 $question->correctanswer[end($keys)] = $format->getpath($answer,
-                        array('#', 'correctanswer', 0, '#'), 0);
+                    ['#', 'correctanswer', 0, '#'], 0);
             }
         }
 
@@ -325,6 +346,7 @@ public function import_from_xml($data, $question, qformat_xml $format, $extra=nu
         return $question;
     }
 
+    #[\Override]
     public function export_to_xml($question, qformat_xml $format, $extra = null) {
         $output = '';
 
@@ -341,6 +363,7 @@ public function export_to_xml($question, qformat_xml $format, $extra = null) {
         return $output;
     }
 
+    #[\Override]
     public function move_files($questionid, $oldcontextid, $newcontextid) {
         $fs = get_file_storage();
 
@@ -356,6 +379,7 @@ public function move_files($questionid, $oldcontextid, $newcontextid) {
                 $newcontextid, 'question', 'incorrectfeedback', $questionid);
     }
 
+    #[\Override]
     protected function delete_files($questionid, $contextid) {
         $fs = get_file_storage();
 
@@ -377,7 +401,7 @@ protected function delete_files($questionid, $contextid) {
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class qtype_oumultiresponse_hint extends question_hint_with_parts {
-    /** @var boolean whether to show the feedback for each choice. */
+    /** @var bool whether to show the feedback for each choice. */
     public $showchoicefeedback;
 
     /**
@@ -403,10 +427,11 @@ public static function load_from_record($row) {
                 $row->shownumcorrect, $row->clearwrong, !empty($row->options));
     }
 
+    #[\Override]
     public function adjust_display_options(question_display_options $options) {
         parent::adjust_display_options($options);
         if (defined('qtype_multichoice::COMBINED_BUT_NOT_CHOICE_FEEDBACK')) {
-            // Newer Moodle versions/
+            // Newer Moodle versions.
             if ($options->feedback && !$this->showchoicefeedback) {
                 $options->feedback = qtype_multichoice::COMBINED_BUT_NOT_CHOICE_FEEDBACK;
             }
diff --git a/renderer.php b/renderer.php
index 8be7161..54587e3 100644
--- a/renderer.php
+++ b/renderer.php
@@ -28,6 +28,9 @@
 require_once($CFG->dirroot . '/question/type/multichoice/renderer.php');
 require_once($CFG->dirroot . '/question/type/oumultiresponse/lib.php');
 
+/**
+ * Class renderer for the OU multiple response question type.
+ */
 class qtype_oumultiresponse_renderer extends qtype_multichoice_multi_renderer {
 
     /**
diff --git a/tests/behat/backup_and_restore.feature b/tests/behat/backup_and_restore.feature
index 1910466..c05f279 100644
--- a/tests/behat/backup_and_restore.feature
+++ b/tests/behat/backup_and_restore.feature
@@ -19,6 +19,8 @@ Feature: Test duplicating a quiz containing an OU multiple response question
       | quiz       | Test quiz | C1     | quiz1    |
     And quiz "Test quiz" contains the following questions:
       | oumultiresponse 001 | 1 |
+    And the following config values are set as admin:
+      | enableasyncbackup | 0 |
 
   @javascript
   Scenario: Backup and restore a course containing an OU multiple response question
diff --git a/tests/behat/preview.feature b/tests/behat/preview.feature
index 34adc3b..ea0537e 100644
--- a/tests/behat/preview.feature
+++ b/tests/behat/preview.feature
@@ -25,7 +25,7 @@ Feature: Preview an OU multiple response question
     When I am on the "oumultiresponse 001" "core_question > preview" page logged in as teacher
     And I expand all fieldsets
     And I set the field "How questions behave" to "Immediate feedback"
-    And I press "Start again with these options"
+    And I press "id_saverestart"
     And I click on "One" "qtype_multichoice > Answer"
     And I click on "Two" "qtype_multichoice > Answer"
     And I press "Check"
@@ -38,7 +38,7 @@ Feature: Preview an OU multiple response question
     When I am on the "oumultiresponse 001" "core_question > preview" page logged in as teacher
     And I expand all fieldsets
     And I set the field "How questions behave" to "Immediate feedback"
-    And I press "Start again with these options"
+    And I press "id_saverestart"
     And I click on "One" "qtype_multichoice > Answer"
     And I click on "Three" "qtype_multichoice > Answer"
     And I press "Check"
@@ -60,7 +60,7 @@ Feature: Preview an OU multiple response question
     And I am on the "oumultiresponse 002" "core_question > preview" page
     And I expand all fieldsets
     And I set the field "How questions behave" to "Immediate feedback"
-    And I press "Start again with these options"
+    And I press "id_saverestart"
     And I click on "One" "qtype_multichoice > Answer"
     And I click on "Two" "qtype_multichoice > Answer"
     And I press "Check"
diff --git a/tests/helper.php b/tests/helper.php
index 6601397..f14b8ae 100644
--- a/tests/helper.php
+++ b/tests/helper.php
@@ -29,14 +29,22 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class qtype_oumultiresponse_test_helper {
+
+    /**
+     * Get test question function.
+     *
+     * @return array
+     */
     public function get_test_questions() {
-        return array('two_of_four', 'two_of_five');
+        return ['two_of_four', 'two_of_five'];
     }
 
     /**
+     * Create a question of type oumultiresponse with two correct answers out of four.
+     *
      * @return qtype_oumultiresponse_question
      */
-    public static function make_oumultiresponse_question_two_of_four() {
+    public static function make_oumultiresponse_question_two_of_four(): qtype_oumultiresponse_question {
 
         question_bank::load_question_definition_classes('oumultiresponse');
         $mc = new qtype_oumultiresponse_question();
@@ -54,17 +62,17 @@ public static function make_oumultiresponse_question_two_of_four() {
 
         test_question_maker::set_standard_combined_feedback_fields($mc);
 
-        $mc->answers = array(
+        $mc->answers = [
             13 => new question_answer(13, 'One', 1, 'One is odd.', FORMAT_HTML),
             14 => new question_answer(14, 'Two', 0, 'Two is even.', FORMAT_HTML),
             15 => new question_answer(15, 'Three', 1, 'Three is odd.', FORMAT_HTML),
             16 => new question_answer(16, 'Four', 0, 'Four is even.', FORMAT_HTML),
-        );
+        ];
 
-        $mc->hints = array(
+        $mc->hints = [
             new qtype_oumultiresponse_hint(1, 'Hint 1.', FORMAT_HTML, true, false, false),
             new qtype_oumultiresponse_hint(2, 'Hint 2.', FORMAT_HTML, true, true, true),
-        );
+        ];
 
         return $mc;
     }
@@ -115,67 +123,69 @@ public static function get_oumultiresponse_question_data_two_of_four() {
                 test_question_maker::STANDARD_OVERALL_INCORRECT_FEEDBACK;
         $qdata->options->incorrectfeedbackformat = FORMAT_HTML;
 
-        $qdata->options->answers = array(
-            13 => (object) array(
+        $qdata->options->answers = [
+            13 => (object) [
                 'id' => 13,
                 'answer' => 'One',
                 'answerformat' => FORMAT_PLAIN,
                 'fraction' => 1,
                 'feedback' => 'One is odd.',
                 'feedbackformat' => FORMAT_HTML,
-            ),
-            14 => (object) array(
+            ],
+            14 => (object) [
                 'id' => 14,
                 'answer' => 'Two',
                 'answerformat' => FORMAT_PLAIN,
                 'fraction' => 0,
                 'feedback' => 'Two is even.',
                 'feedbackformat' => FORMAT_HTML,
-            ),
-            15 => (object) array(
+            ],
+            15 => (object) [
                 'id' => 15,
                 'answer' => 'Three',
                 'answerformat' => FORMAT_PLAIN,
                 'fraction' => 1,
                 'feedback' => 'Three is odd.',
                 'feedbackformat' => FORMAT_HTML,
-            ),
-            16 => (object) array(
+            ],
+            16 => (object) [
                 'id' => 16,
                 'answer' => 'Four',
                 'answerformat' => FORMAT_PLAIN,
                 'fraction' => 0,
                 'feedback' => 'Four is even.',
                 'feedbackformat' => FORMAT_HTML,
-            ),
-        );
+            ],
+        ];
 
-        $qdata->hints = array(
-            1 => (object) array(
+        $qdata->hints = [
+            1 => (object) [
                 'id' => 1,
                 'hint' => 'Hint 1.',
                 'hintformat' => FORMAT_HTML,
                 'shownumcorrect' => 1,
                 'clearwrong' => 0,
                 'options' => 0,
-            ),
-            2 => (object) array(
+            ],
+            2 => (object) [
                 'id' => 2,
                 'hint' => 'Hint 2.',
                 'hintformat' => FORMAT_HTML,
                 'shownumcorrect' => 1,
                 'clearwrong' => 1,
                 'options' => 1,
-            ),
-        );
+            ],
+        ];
 
         return $qdata;
     }
 
     /**
+     * Make oumultiresponse question with two correct answers out of five.
+     *
      * @return qtype_oumultiresponse_question
      */
-    public static function make_oumultiresponse_question_two_of_five() {
+    public static function make_oumultiresponse_question_two_of_five(): qtype_oumultiresponse_question {
         question_bank::load_question_definition_classes('oumultiresponse');
         $mc = new qtype_oumultiresponse_question();
 
@@ -192,53 +202,55 @@ public static function make_oumultiresponse_question_two_of_five() {
 
         test_question_maker::set_standard_combined_feedback_fields($mc);
 
-        $mc->answers = array(
+        $mc->answers = [
             13 => new question_answer(13, 'A', 1, '', FORMAT_HTML),
             14 => new question_answer(14, 'B', 1, '', FORMAT_HTML),
             15 => new question_answer(15, 'C', 0, '', FORMAT_HTML),
             16 => new question_answer(16, 'D', 0, '', FORMAT_HTML),
             17 => new question_answer(17, 'E', 0, '', FORMAT_HTML),
-        );
+        ];
 
-        $mc->hints = array(
+        $mc->hints = [
             1 => new qtype_oumultiresponse_hint(1, 'Hint 1.', FORMAT_HTML, true, false, false),
             2 => new qtype_oumultiresponse_hint(2, 'Hint 2.', FORMAT_HTML, true, true, true),
-        );
+        ];
 
         return $mc;
     }
 
     /**
+     * Get oumultiresponse question form data for a question with two correct answers out of four.
+     *
      * @return stdClass date to create an oumultiresponse question.
      */
-    public function get_oumultiresponse_question_form_data_two_of_four() {
+    public function get_oumultiresponse_question_form_data_two_of_four(): stdClass {
         $fromform = new stdClass();
 
         $fromform->name = 'OU multiple response question';
-        $fromform->questiontext = array('text' => 'Which are the odd numbers?', 'format' => FORMAT_HTML);
+        $fromform->questiontext = ['text' => 'Which are the odd numbers?', 'format' => FORMAT_HTML];
         $fromform->defaultmark = 1.0;
-        $fromform->generalfeedback = array('text' => 'The odd numbers are One and Three.', 'format' => FORMAT_HTML);
+        $fromform->generalfeedback = ['text' => 'The odd numbers are One and Three.', 'format' => FORMAT_HTML];
         $fromform->shuffleanswers = 0;
         $fromform->answernumbering = 'abc';
         $fromform->showstandardinstruction = 0;
-        $fromform->answer = array(
-                0 => array('text' => 'One', 'format' => FORMAT_PLAIN),
-                1 => array('text' => 'Two', 'format' => FORMAT_PLAIN),
-                2 => array('text' => 'Three', 'format' => FORMAT_PLAIN),
-                3 => array('text' => 'Four', 'format' => FORMAT_PLAIN)
-        );
-        $fromform->correctanswer = array(
-                0 => 1,
-                1 => 0,
-                2 => 1,
-                3 => 0
-        );
-        $fromform->feedback = array(
-                0 => array('text' => 'One is odd.', 'format' => FORMAT_HTML),
-                1 => array('text' => 'Two is even.', 'format' => FORMAT_HTML),
-                2 => array('text' => 'Three is odd.', 'format' => FORMAT_HTML),
-                3 => array('text' => 'Four is odd.', 'format' => FORMAT_HTML)
-        );
+        $fromform->answer = [
+            0 => ['text' => 'One', 'format' => FORMAT_PLAIN],
+            1 => ['text' => 'Two', 'format' => FORMAT_PLAIN],
+            2 => ['text' => 'Three', 'format' => FORMAT_PLAIN],
+            3 => ['text' => 'Four', 'format' => FORMAT_PLAIN],
+        ];
+        $fromform->correctanswer = [
+            0 => 1,
+            1 => 0,
+            2 => 1,
+            3 => 0,
+        ];
+        $fromform->feedback = [
+            0 => ['text' => 'One is odd.', 'format' => FORMAT_HTML],
+            1 => ['text' => 'Two is even.', 'format' => FORMAT_HTML],
+            2 => ['text' => 'Three is odd.', 'format' => FORMAT_HTML],
+            3 => ['text' => 'Four is odd.', 'format' => FORMAT_HTML],
+        ];
         test_question_maker::set_standard_combined_feedback_form_data($fromform);
         $fromform->shownumcorrect = 0;
         $fromform->penalty = 0.3333333;
diff --git a/tests/privacy_provider_test.php b/tests/privacy_provider_test.php
index 55d8770..6790fb3 100644
--- a/tests/privacy_provider_test.php
+++ b/tests/privacy_provider_test.php
@@ -24,7 +24,7 @@
 namespace qtype_oumultiresponse;
 
 use core_privacy\local\metadata\collection;
-use \core_privacy\local\request\user_preference_provider;
+use core_privacy\local\request\user_preference_provider;
 use qtype_oumultiresponse\privacy\provider;
 use core_privacy\local\request\writer;
 use core_privacy\local\request\transform;
@@ -40,17 +40,18 @@
  * @package    qtype_oumultiresponse
  * @copyright  2021 The Open university
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers \qtype_oumultiresponse\privacy\provider
  */
-class privacy_provider_test extends \core_privacy\tests\provider_testcase {
+final class privacy_provider_test extends \core_privacy\tests\provider_testcase {
     // Include the privacy helper which has assertions on it.
 
-    public function test_get_metadata() {
+    public function test_get_metadata(): void {
         $collection = new \core_privacy\local\metadata\collection('qtype_oumultiresponse');
         $actual = \qtype_oumultiresponse\privacy\provider::get_metadata($collection);
         $this->assertEquals($collection, $actual);
     }
 
-    public function test_export_user_preferences_no_pref() {
+    public function test_export_user_preferences_no_pref(): void {
         $this->resetAfterTest();
 
         $user = $this->getDataGenerator()->create_user();
@@ -67,7 +68,7 @@ public function test_export_user_preferences_no_pref() {
      * @param string $value The value stored in the database
      * @param string $expected The expected transformed value
      */
-    public function test_export_user_preferences($name, $value, $expected) {
+    public function test_export_user_preferences($name, $value, $expected): void {
         $this->resetAfterTest();
         $user = $this->getDataGenerator()->create_user();
         set_user_preference("qtype_oumultiresponse_$name", $value, $user);
@@ -91,7 +92,7 @@ public function test_export_user_preferences($name, $value, $expected) {
      *
      * @return array Array of valid user preferences.
      */
-    public function user_preference_provider() {
+    public static function user_preference_provider(): array {
         return [
                 'default mark 2' => ['defaultmark', 2, 2],
                 'penalty 33.33333%' => ['penalty', 0.3333333, '33.33333%'],
@@ -103,7 +104,7 @@ public function user_preference_provider() {
                 'answernumbering iii' => ['answernumbering', 'iii', 'i., ii., iii., ...'],
                 'answernumbering III' => ['answernumbering', 'IIII', 'I., II., III., ...'],
                 'show standard instruction yes' => ['showstandardinstruction', 1, 'Yes'],
-                'show standard instruction no' => ['showstandardinstruction', 0, 'No']
+                'show standard instruction no' => ['showstandardinstruction', 0, 'No'],
         ];
     }
 }
diff --git a/tests/question_test.php b/tests/question_test.php
index f6733b5..3340068 100644
--- a/tests/question_test.php
+++ b/tests/question_test.php
@@ -41,207 +41,215 @@
  *
  * @copyright  2008 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers ::replace_char_at
+ * @covers ::grade_response
+ * @covers ::grade_computation
  */
+final class question_test extends \basic_testcase {
 
-class question_test extends \basic_testcase {
+    /**
+     * Tolerance for floating point comparisons.
+     *
+     * @var float
+     */
     private $tolerance = 0.000001;
 
-    public function test_replace_char_at() {
+    public function test_replace_char_at(): void {
         $this->assertEquals(qtype_oumultiresponse_question::replace_char_at('220', 0, '0'), '020');
     }
 
-    public function test_grade_responses_right_right() {
+    public function test_grade_responses_right_right(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array('choice0' => '1', 'choice2' => '1'));
+        list($fraction, $state) = $mc->grade_response(['choice0' => '1', 'choice2' => '1']);
         $this->assertEquals(1, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedright);
     }
 
-    public function test_grade_responses_right() {
+    public function test_grade_responses_right(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array('choice0' => '1'));
+        list($fraction, $state) = $mc->grade_response(['choice0' => '1']);
         $this->assertEquals(0.5, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedpartial);
     }
 
-    public function test_grade_responses_wrong_wrong() {
+    public function test_grade_responses_wrong_wrong(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array('choice1' => '1', 'choice3' => '1'));
+        list($fraction, $state) = $mc->grade_response(['choice1' => '1', 'choice3' => '1']);
         $this->assertEquals(0, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedwrong);
     }
 
-    public function test_grade_responses_right_wrong_wrong() {
+    public function test_grade_responses_right_wrong_wrong(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
         list($fraction, $state) = $mc->grade_response(
-                array('choice0' => '1', 'choice1' => '1', 'choice3' => '1'));
+            ['choice0' => '1', 'choice1' => '1', 'choice3' => '1']);
         $this->assertEquals(0, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedpartial);
     }
 
-    public function test_grade_responses_right_wrong() {
+    public function test_grade_responses_right_wrong(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array('choice0' => '1', 'choice1' => '1'));
+        list($fraction, $state) = $mc->grade_response(['choice0' => '1', 'choice1' => '1']);
         $this->assertEquals(0.5, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedpartial);
     }
 
-    public function test_grade_responses_right_right_wrong() {
+    public function test_grade_responses_right_right_wrong(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array(
-                'choice0' => '1', 'choice2' => '1', 'choice3' => '1'));
+        list($fraction, $state) = $mc->grade_response([
+            'choice0' => '1', 'choice2' => '1', 'choice3' => '1']);
         $this->assertEquals(0.5, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedpartial);
     }
 
-    public function test_grade_responses_right_right_wrong_wrong() {
+    public function test_grade_responses_right_right_wrong_wrong(): void {
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->shuffleanswers = false;
         $mc->start_attempt(new question_attempt_step(), 1);
 
-        list($fraction, $state) = $mc->grade_response(array(
-                'choice0' => '1', 'choice1' => '1', 'choice2' => '1', 'choice3' => '1'));
+        list($fraction, $state) = $mc->grade_response([
+            'choice0' => '1', 'choice1' => '1', 'choice2' => '1', 'choice3' => '1']);
         $this->assertEquals(0, $fraction, '', $this->tolerance);
         $this->assertEquals($state, question_state::$gradedpartial);
     }
 
-    public function test_grade_computation() {
+    public function test_grade_computation(): void {
         $right = new \stdClass();
         $right->fraction = 1.0;
         $wrong = new \stdClass();
         $wrong->fraction = 0.0;
 
         $penalty = 0.3333333;
-        $answers = array($right, $right, $right, $wrong, $wrong, $wrong);
+        $answers = [$right, $right, $right, $wrong, $wrong, $wrong];
 
-        $responsehistory = array('111', '000', '000', '000', '000', '000');
+        $responsehistory = ['111', '000', '000', '000', '000', '000'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.3333333, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '000', '000', '000', '000');
+        $responsehistory = ['111', '111', '000', '000', '000', '000'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.6666667, $this->tolerance, '');
 
-        $responsehistory = array('1', '1', '1', '0', '0', '0');
+        $responsehistory = ['1', '1', '1', '0', '0', '0'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 1.0, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '111', '000', '000');
+        $responsehistory = ['111', '111', '111', '111', '000', '000'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.6666667, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '111', '111', '000');
+        $responsehistory = ['111', '111', '111', '111', '111', '000'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.3333333, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '111', '111', '111');
+        $responsehistory = ['111', '111', '111', '111', '111', '111'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.0, $this->tolerance, '');
 
-        $responsehistory = array('011', '000', '000', '100', '111', '111');
+        $responsehistory = ['011', '000', '000', '100', '111', '111'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('001', '000', '000', '110', '111', '111');
+        $responsehistory = ['001', '000', '000', '110', '111', '111'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.1111111, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '001', '100', '010', '000');
+        $responsehistory = ['111', '111', '001', '100', '010', '000'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.7777778, $this->tolerance, '');
 
-        $responsehistory = array('100', '100', '001', '100', '011', '001');
+        $responsehistory = ['100', '100', '001', '100', '011', '001'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.1111111, $this->tolerance, '');
 
-        $responsehistory = array('101', '101', '001', '110', '011', '111');
+        $responsehistory = ['101', '101', '001', '110', '011', '111'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.1111111, $this->tolerance, '');
 
-        $responsehistory = array('011', '001', '001', '100', '110', '111');
+        $responsehistory = ['011', '001', '001', '100', '110', '111'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.3333333, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '110', '110', '100');
+        $responsehistory = ['111', '111', '111', '110', '110', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.4444444, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '110', '100', '100');
+        $responsehistory = ['111', '111', '111', '110', '100', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.5555556, $this->tolerance, '');
 
-        $responsehistory = array('110', '101', '101', '111', '110', '100');
+        $responsehistory = ['110', '101', '101', '111', '110', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('111', '110', '110', '111', '111', '100');
+        $responsehistory = ['111', '110', '110', '111', '111', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('011', '111', '110', '111', '111', '100');
+        $responsehistory = ['011', '111', '110', '111', '111', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('110', '111', '110', '111', '111', '100');
+        $responsehistory = ['110', '111', '110', '111', '111', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('111', '111', '111', '110', '110', '100');
+        $responsehistory = ['111', '111', '111', '110', '110', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.4444444, $this->tolerance, '');
 
-        $responsehistory = array('110', '111', '110', '111', '111', '100');
+        $responsehistory = ['110', '111', '110', '111', '111', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('011', '111', '110', '111', '111', '100');
+        $responsehistory = ['011', '111', '110', '111', '111', '100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.2222222, $this->tolerance, '');
 
-        $responsehistory = array('011', '111', '110', '110', '111', '001');
+        $responsehistory = ['011', '111', '110', '110', '111', '001'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.3333333, $this->tolerance, '');
 
-        $responsehistory = array('11', '01', '01', '10', '10', '00');
+        $responsehistory = ['11', '01', '01', '10', '10', '00'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 3), 0.7777778, $this->tolerance, '');
 
         $penalty = 0.2;
-        $answers = array($right, $right, $right, $right, $wrong, $wrong, $wrong, $wrong);
-        $responsehistory = array(
-                '11111', '10111', '11100', '11011', '10011', '01010', '01000', '00100');
+        $answers = [$right, $right, $right, $right, $wrong, $wrong, $wrong, $wrong];
+        $responsehistory = [
+                '11111', '10111', '11100', '11011', '10011', '01010', '01000', '00100'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 5), 0.45, $this->tolerance, '');
 
         $penalty = 0.33334;
-        $answers = array($right, $right, $wrong, $wrong, $wrong);
-        $responsehistory = array('0', '0', '1', '1', '0');
+        $answers = [$right, $right, $wrong, $wrong, $wrong];
+        $responsehistory = ['0', '0', '1', '1', '0'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 1), 0.0, $this->tolerance, '');
 
-        $responsehistory = array('0', '1', '1', '0', '0');
+        $responsehistory = ['0', '1', '1', '0', '0'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 1), 0.5, $this->tolerance, '');
 
-        $responsehistory = array('1', '1', '0', '0', '0');
+        $responsehistory = ['1', '1', '0', '0', '0'];
         $this->assertEqualsWithDelta(qtype_oumultiresponse_question::grade_computation(
                 $responsehistory, $answers, $penalty, 1), 1.0, $this->tolerance, '');
     }
diff --git a/tests/questiontype_test.php b/tests/questiontype_test.php
index ae03f0c..cc8c7a3 100644
--- a/tests/questiontype_test.php
+++ b/tests/questiontype_test.php
@@ -42,27 +42,30 @@
  *
  * @copyright  2008 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers \qtype_oumultiresponse
  */
-class questiontype_test extends \question_testcase {
+final class questiontype_test extends \question_testcase {
     /**
      * @var qtype_oumultiresponse
      */
     private $qtype;
 
     public function setUp(): void {
+        parent::setUp();
         $this->qtype = new qtype_oumultiresponse();
     }
 
-    public function assert_same_xml($expectedxml, $xml) {
+    #[\Override]
+    public function assert_same_xml($expectedxml, $xml): void {
         $this->assertEquals(str_replace("\r\n", "\n", $expectedxml),
                 str_replace("\r\n", "\n", $xml));
     }
 
-    public function test_name() {
+    public function test_name(): void {
         $this->assertEquals($this->qtype->name(), 'oumultiresponse');
     }
 
-    public function test_initialise_question_instance() {
+    public function test_initialise_question_instance(): void {
         $qdata = test_question_maker::get_question_data('oumultiresponse', 'two_of_four');
         $expectedq = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $qdata->stamp = $expectedq->stamp;
@@ -75,36 +78,36 @@ public function test_initialise_question_instance() {
         $this->assertEquals($expectedq, $question);
     }
 
-    public function test_can_analyse_responses() {
+    public function test_can_analyse_responses(): void {
         $this->assertTrue($this->qtype->can_analyse_responses());
     }
 
-    public function test_get_possible_responses() {
+    public function test_get_possible_responses(): void {
         $q = new \stdClass();
         $q->id = 1;
         $q->options = new \stdClass();
         $q->options->answers = [
-            1 => (object) array('answer' => 'frog', 'fraction' => 1),
-            2 => (object) array('answer' => 'toad', 'fraction' => 1),
-            3 => (object) array('answer' => 'newt', 'fraction' => 0),
+            1 => (object) ['answer' => 'frog', 'fraction' => 1],
+            2 => (object) ['answer' => 'toad', 'fraction' => 1],
+            3 => (object) ['answer' => 'newt', 'fraction' => 0],
         ];
         $responses = $this->qtype->get_possible_responses($q);
 
-        $this->assertEquals(array(
-            1 => array(1 => new question_possible_response('frog', 0.5)),
-            2 => array(2 => new question_possible_response('toad', 0.5)),
-            3 => array(3 => new question_possible_response('newt', 0)),
-        ), $this->qtype->get_possible_responses($q));
+        $this->assertEquals([
+            1 => [1 => new question_possible_response('frog', 0.5)],
+            2 => [2 => new question_possible_response('toad', 0.5)],
+            3 => [3 => new question_possible_response('newt', 0)],
+        ], $this->qtype->get_possible_responses($q));
     }
 
-    public function test_get_random_guess_score() {
+    public function test_get_random_guess_score(): void {
         $questiondata = new \stdClass();
         $questiondata->options = new \stdClass();
-        $questiondata->options->answers = array(
+        $questiondata->options->answers = [
             1 => new question_answer(1, 'A', 1, '', FORMAT_HTML),
             2 => new question_answer(2, 'B', 0, '', FORMAT_HTML),
             3 => new question_answer(3, 'C', 0, '', FORMAT_HTML),
-        );
+        ];
         $this->assertEquals(1 / 3,
                 $this->qtype->get_random_guess_score($questiondata), '', 0.000001);
 
@@ -117,7 +120,7 @@ public function test_get_random_guess_score() {
                 $this->qtype->get_random_guess_score($questiondata), '', 0.000001);
     }
 
-    public function test_xml_import() {
+    public function test_xml_import(): void {
         $xml = '  <question type="oumultiresponse">
     <name>
       <text>OU multiple response question</text>
@@ -196,44 +199,51 @@ public function test_xml_import() {
         $expectedq->penalty = 0.3333333;
 
         $expectedq->shuffleanswers = 1;
-        $expectedq->correctfeedback = array('text' => 'Well done.',
-                'format' => FORMAT_HTML);
-        $expectedq->partiallycorrectfeedback = array('text' => 'Not entirely.',
-                'format' => FORMAT_HTML);
+        $expectedq->correctfeedback = [
+            'text' => 'Well done.',
+            'format' => FORMAT_HTML,
+        ];
+        $expectedq->partiallycorrectfeedback = [
+            'text' => 'Not entirely.',
+            'format' => FORMAT_HTML,
+        ];
         $expectedq->shownumcorrect = false;
-        $expectedq->incorrectfeedback = array('text' => 'Completely wrong!',
-                'format' => FORMAT_HTML);
-
-        $expectedq->answer = array(
-            array('text' => 'One', 'format' => FORMAT_HTML),
-            array('text' => 'Two', 'format' => FORMAT_HTML),
-            array('text' => 'Three', 'format' => FORMAT_HTML),
-            array('text' => 'Four', 'format' => FORMAT_HTML),
-        );
-        $expectedq->correctanswer = array(1, 0, 1, 0);
-        $expectedq->feedback = array(
-            array('text' => 'Specific feedback to correct answer.',
-                    'format' => FORMAT_HTML),
-            array('text' => 'Specific feedback to wrong answer.',
-                    'format' => FORMAT_HTML),
-            array('text' => 'Specific feedback to correct answer.',
-                    'format' => FORMAT_HTML),
-            array('text' => 'Specific feedback to wrong answer.',
-                    'format' => FORMAT_HTML),
-        );
-
-        $expectedq->hint = array(
-                array('text' => 'Try again.', 'format' => FORMAT_HTML),
-                array('text' => 'Hint 2.', 'format' => FORMAT_HTML));
-        $expectedq->hintshownumcorrect = array(true, true);
-        $expectedq->hintclearwrong = array(false, true);
-        $expectedq->hintshowchoicefeedback = array(false, true);
+        $expectedq->incorrectfeedback = [
+            'text' => 'Completely wrong!',
+            'format' => FORMAT_HTML,
+        ];
+
+        $expectedq->answer = [
+            ['text' => 'One', 'format' => FORMAT_HTML],
+            ['text' => 'Two', 'format' => FORMAT_HTML],
+            ['text' => 'Three', 'format' => FORMAT_HTML],
+            ['text' => 'Four', 'format' => FORMAT_HTML],
+        ];
+        $expectedq->correctanswer = [1, 0, 1, 0];
+        $expectedq->feedback = [
+            ['text' => 'Specific feedback to correct answer.',
+                'format' => FORMAT_HTML],
+            ['text' => 'Specific feedback to wrong answer.',
+                'format' => FORMAT_HTML],
+            ['text' => 'Specific feedback to correct answer.',
+                'format' => FORMAT_HTML],
+            ['text' => 'Specific feedback to wrong answer.',
+                'format' => FORMAT_HTML],
+        ];
+
+        $expectedq->hint = [
+            ['text' => 'Try again.', 'format' => FORMAT_HTML],
+            ['text' => 'Hint 2.', 'format' => FORMAT_HTML],
+        ];
+        $expectedq->hintshownumcorrect = [true, true];
+        $expectedq->hintclearwrong = [false, true];
+        $expectedq->hintshowchoicefeedback = [false, true];
 
         $this->assert(new question_check_specified_fields_expectation($expectedq), $q);
         $this->assertEquals($expectedq->answer, $q->answer);
     }
 
-    public function test_xml_import_legacy() {
+    public function test_xml_import_legacy(): void {
         $xml = '  <question type="oumultiresponse">
     <name>
       <text>008 OUMR feedback test</text>
@@ -328,44 +338,51 @@ public function test_xml_import_legacy() {
 
         $expectedq->shuffleanswers = 1;
         $expectedq->answernumbering = 'abc';
-        $expectedq->correctfeedback = array('text' => 'Correct overall feedback',
-                'format' => FORMAT_HTML);
-        $expectedq->partiallycorrectfeedback = array(
-                'text' => 'Partially correct overall feedback.',
-                'format' => FORMAT_HTML);
+        $expectedq->correctfeedback = [
+            'text' => 'Correct overall feedback',
+            'format' => FORMAT_HTML,
+        ];
+        $expectedq->partiallycorrectfeedback = [
+            'text' => 'Partially correct overall feedback.',
+            'format' => FORMAT_HTML,
+        ];
         $expectedq->shownumcorrect = false;
-        $expectedq->incorrectfeedback = array('text' => 'Incorrect overall feedback.',
-                'format' => FORMAT_HTML);
-
-        $expectedq->answer = array(
-            array('text' => 'eighta', 'format' => FORMAT_HTML),
-            array('text' => 'eightb', 'format' => FORMAT_HTML),
-            array('text' => 'one', 'format' => FORMAT_HTML),
-            array('text' => 'two', 'format' => FORMAT_HTML));
-        $expectedq->correctanswer = array(1, 1, 0, 0);
-        $expectedq->feedback = array(
-            array('text' => '<p>Specific feedback to correct answer.</p>',
-                    'format' => FORMAT_HTML),
-            array('text' => '<p>Specific feedback to correct answer.</p>',
-                    'format' => FORMAT_HTML),
-            array('text' => '<p>Specific feedback to wrong answer.</p>',
-                    'format' => FORMAT_HTML),
-            array('text' => '<p>Specific feedback to wrong answer.</p>',
-                    'format' => FORMAT_HTML),
-        );
-
-        $expectedq->hint = array(
-                array('text' => 'Hint 1.', 'format' => FORMAT_HTML),
-                array('text' => 'Hint 2.', 'format' => FORMAT_HTML));
-        $expectedq->hintshownumcorrect = array(false, false);
-        $expectedq->hintclearwrong = array(false, false);
-        $expectedq->hintshowchoicefeedback = array(true, true);
+        $expectedq->incorrectfeedback = [
+            'text' => 'Incorrect overall feedback.',
+            'format' => FORMAT_HTML,
+        ];
+
+        $expectedq->answer = [
+            ['text' => 'eighta', 'format' => FORMAT_HTML],
+            ['text' => 'eightb', 'format' => FORMAT_HTML],
+            ['text' => 'one', 'format' => FORMAT_HTML],
+            ['text' => 'two', 'format' => FORMAT_HTML],
+        ];
+        $expectedq->correctanswer = [1, 1, 0, 0];
+        $expectedq->feedback = [
+            ['text' => '<p>Specific feedback to correct answer.</p>',
+                'format' => FORMAT_HTML],
+            ['text' => '<p>Specific feedback to correct answer.</p>',
+                'format' => FORMAT_HTML],
+            ['text' => '<p>Specific feedback to wrong answer.</p>',
+                'format' => FORMAT_HTML],
+            ['text' => '<p>Specific feedback to wrong answer.</p>',
+                'format' => FORMAT_HTML],
+        ];
+
+        $expectedq->hint = [
+            ['text' => 'Hint 1.', 'format' => FORMAT_HTML],
+            ['text' => 'Hint 2.', 'format' => FORMAT_HTML],
+        ];
+        $expectedq->hintshownumcorrect = [false, false];
+        $expectedq->hintclearwrong = [false, false];
+        $expectedq->hintshowchoicefeedback = [true, true];
 
         $this->assertEquals($expectedq->answer, $q->answer);
         $this->assert(new question_check_specified_fields_expectation($expectedq), $q);
     }
 
-    public function test_xml_export() {
+    public function test_xml_export(): void {
         $qdata = test_question_maker::get_question_data('oumultiresponse', 'two_of_four');
         $qdata->defaultmark = 6;
 
diff --git a/tests/walkthrough_test.php b/tests/walkthrough_test.php
index 371ba10..b368d27 100644
--- a/tests/walkthrough_test.php
+++ b/tests/walkthrough_test.php
@@ -44,10 +44,11 @@
  *
  * @copyright  2010 The Open University
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers \qtype_oumultiresponse_question
  */
-class walkthrough_test extends \qbehaviour_walkthrough_test_base {
+final class walkthrough_test extends \qbehaviour_walkthrough_test_base {
 
-    public function test_shows_standrd_instruction_yes() {
+    public function test_shows_standrd_instruction_yes(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
@@ -61,7 +62,7 @@ public function test_shows_standrd_instruction_yes() {
         $this->assertStringContainsString($standardinstruction, $this->currentoutput);
     }
 
-    public function test_shows_standrd_instruction_no() {
+    public function test_shows_standrd_instruction_no(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
@@ -70,14 +71,18 @@ public function test_shows_standrd_instruction_no() {
         $this->start_attempt_at_question($mc, 'interactive', 3);
         $this->render();
 
+        $standardinstructionclass = 'prompt h6 fw-normal visually-hidden';
+        if (utils::moodle_version_is("<=" , "45")) {
+            $standardinstructionclass = 'prompt h6 font-weight-normal sr-only';
+        }
         // Check for 'Show standard instruction'.
         $standardinstruction = \html_writer::tag('legend', get_string('answer'), [
-            'class' => 'prompt h6 font-weight-normal sr-only'
+            'class' => $standardinstructionclass,
         ]);
         $this->assertStringContainsString($standardinstruction, $this->currentoutput);
     }
 
-    public function test_interactive_behaviour() {
+    public function test_interactive_behaviour(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
@@ -101,7 +106,7 @@ public function test_interactive_behaviour() {
                 $this->get_no_hint_visible_expectation());
 
         // Save the wrong answer.
-        $this->process_submission(array('choice1' => '1', 'choice3' => '1'));
+        $this->process_submission(['choice1' => '1', 'choice3' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -119,7 +124,7 @@ public function test_interactive_behaviour() {
                 $this->get_no_hint_visible_expectation());
 
         // Submit the wrong answer.
-        $this->process_submission(array('choice1' => '1', 'choice3' => '1', '-submit' => '1'));
+        $this->process_submission(['choice1' => '1', 'choice3' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -144,7 +149,7 @@ public function test_interactive_behaviour() {
                         $this->quba->get_field_prefix($this->slot) . 'choice3'));
 
         // Do try again.
-        $this->process_submission(array('-tryagain' => 1));
+        $this->process_submission(['-tryagain' => 1]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -162,7 +167,7 @@ public function test_interactive_behaviour() {
                 $this->get_no_hint_visible_expectation());
 
         // Submit a partially right answer.
-        $this->process_submission(array('choice0' => '1', 'choice3' => '1', '-submit' => '1'));
+        $this->process_submission(['choice0' => '1', 'choice3' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -187,7 +192,7 @@ public function test_interactive_behaviour() {
                         $this->quba->get_field_prefix($this->slot) . 'choice3', '0'));
 
         // Do try again.
-        $this->process_submission(array('choice0' => '1', '-tryagain' => 1));
+        $this->process_submission(['choice0' => '1', '-tryagain' => 1]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -205,7 +210,7 @@ public function test_interactive_behaviour() {
                 $this->get_no_hint_visible_expectation());
 
         // Submit the right answer.
-        $this->process_submission(array('choice0' => '1', 'choice2' => '1', '-submit' => '1'));
+        $this->process_submission(['choice0' => '1', 'choice2' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$gradedright);
@@ -220,15 +225,15 @@ public function test_interactive_behaviour() {
                 $this->get_contains_standard_correct_combined_feedback_expectation());
     }
 
-    public function test_interactive_behaviour2() {
+    public function test_interactive_behaviour2(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
         $mc->showstandardinstruction = 1;
-        $mc->hints = array(
+        $mc->hints = [
             new qtype_oumultiresponse_hint(1, 'Hint 1', FORMAT_HTML, true, true, true),
             new qtype_oumultiresponse_hint(2, 'Hint 2', FORMAT_HTML, true, true, true),
-        );
+        ];
         $mc->shuffleanswers = false;
         $mc->showstandardinstruction = true;
         $this->start_attempt_at_question($mc, 'interactive', 3);
@@ -251,8 +256,8 @@ public function test_interactive_behaviour2() {
                         preg_quote(get_string('selectmulti', 'qtype_multichoice'), '/') . '/'));
 
         // Submit the wrong answer with too manu options selected.
-        $this->process_submission(array(
-                'choice1' => '1', 'choice2' => '1', 'choice3' => '1', '-submit' => '1'));
+        $this->process_submission([
+            'choice1' => '1', 'choice2' => '1', 'choice3' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -281,14 +286,14 @@ public function test_interactive_behaviour2() {
                         preg_quote(get_string('selectmulti', 'qtype_multichoice'), '/') . '/'));
     }
 
-    public function test_interactive_clear_wrong() {
+    public function test_interactive_clear_wrong(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_four');
-        $mc->hints = array(
+        $mc->hints = [
             new qtype_oumultiresponse_hint(1, 'Hint 1', FORMAT_HTML, true, true, true),
             new qtype_oumultiresponse_hint(2, 'Hint 2', FORMAT_HTML, true, true, true),
-        );
+        ];
         $mc->shuffleanswers = false;
         $mc->showstandardinstruction = true;
         $this->start_attempt_at_question($mc, 'interactive', 3);
@@ -310,7 +315,7 @@ public function test_interactive_clear_wrong() {
                 $this->get_no_hint_visible_expectation());
 
         // Submit a wrong answer.
-        $this->process_submission(array('choice1' => '1', 'choice3' => '1', '-submit' => '1'));
+        $this->process_submission(['choice1' => '1', 'choice3' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -332,7 +337,7 @@ public function test_interactive_clear_wrong() {
                         $this->quba->get_field_prefix($this->slot) . 'choice3', '0'));
 
         // Try again.
-        $this->process_submission(array('choice1' => '0', 'choice3' => '0', '-tryagain' => '1'));
+        $this->process_submission(['choice1' => '0', 'choice3' => '0', '-tryagain' => '1']);
 
         // Vreify.
         $this->check_current_state(question_state::$todo);
@@ -351,7 +356,7 @@ public function test_interactive_clear_wrong() {
                 $this->get_no_hint_visible_expectation());
 
         // Submit a partially right answer.
-        $this->process_submission(array('choice0' => '1', 'choice3' => '1', '-submit' => '1'));
+        $this->process_submission(['choice0' => '1', 'choice3' => '1', '-submit' => '1']);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -373,7 +378,7 @@ public function test_interactive_clear_wrong() {
                         $this->quba->get_field_prefix($this->slot) . 'choice3', '0'));
 
         // Try again.
-        $this->process_submission(array('choice0' => '1', 'choice3' => '0', '-tryagain' => '1'));
+        $this->process_submission(['choice0' => '1', 'choice3' => '0', '-tryagain' => '1']);
 
         // Check the initial state.
         $this->check_current_state(question_state::$todo);
@@ -392,7 +397,7 @@ public function test_interactive_clear_wrong() {
                 $this->get_no_hint_visible_expectation());
     }
 
-    public function test_interactive_bug_11263() {
+    public function test_interactive_bug_11263(): void {
 
         // Create a multichoice single question.
         $mc = test_question_maker::make_question('oumultiresponse', 'two_of_five');
@@ -406,28 +411,28 @@ public function test_interactive_bug_11263() {
                 $this->get_tries_remaining_expectation(3));
 
         // Submit a wrong answer.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '0',
             'choice1' => '0',
             'choice2' => '0',
             'choice3' => '1',
             'choice4' => '1',
-            '-submit' => '1'
-        ));
+            '-submit' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
         $this->check_current_mark(null);
 
         // Try again.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '0',
             'choice1' => '0',
             'choice2' => '0',
             'choice3' => '1',
             'choice4' => '1',
-            '-tryagain' => '1'
-        ));
+            '-tryagain' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -436,28 +441,28 @@ public function test_interactive_bug_11263() {
                 $this->get_tries_remaining_expectation(2));
 
         // Submit a wrong answer again.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '0',
             'choice1' => '0',
             'choice2' => '0',
             'choice3' => '1',
             'choice4' => '1',
-            '-submit' => '1'
-        ));
+            '-submit' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
         $this->check_current_mark(null);
 
         // Try again - clears wrong.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '0',
             'choice1' => '0',
             'choice2' => '0',
             'choice3' => '0',
             'choice4' => '0',
-            '-tryagain' => '1'
-        ));
+            '-tryagain' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$todo);
@@ -466,21 +471,21 @@ public function test_interactive_bug_11263() {
                 $this->get_tries_remaining_expectation(1));
 
         // Submit one right choice.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '1',
             'choice1' => '0',
             'choice2' => '0',
             'choice3' => '0',
             'choice4' => '0',
-            '-submit' => '1'
-        ));
+            '-submit' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$gradedpartial);
         $this->check_current_mark(0);
     }
 
-    public function test_interactive_regrade_changing_num_tries_leaving_open() {
+    public function test_interactive_regrade_changing_num_tries_leaving_open(): void {
         // Create a multichoice multiple question.
         $q = test_question_maker::make_question('oumultiresponse', 'two_of_five');
         $this->start_attempt_at_question($q, 'interactive', 3);
@@ -492,14 +497,14 @@ public function test_interactive_regrade_changing_num_tries_leaving_open() {
                 $this->get_tries_remaining_expectation(3));
 
         // Submit the right answer.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '1',
             'choice1' => '1',
             'choice2' => '0',
             'choice3' => '0',
             'choice4' => '0',
-            '-submit' => '1'
-        ));
+            '-submit' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$gradedright);
@@ -515,7 +520,7 @@ public function test_interactive_regrade_changing_num_tries_leaving_open() {
         $this->check_current_mark(null);
     }
 
-    public function test_interactive_regrade_changing_num_tries_finished() {
+    public function test_interactive_regrade_changing_num_tries_finished(): void {
         // Create a multichoice multiple question.
         $q = test_question_maker::make_question('oumultiresponse', 'two_of_five');
         $this->start_attempt_at_question($q, 'interactive', 3);
@@ -527,14 +532,14 @@ public function test_interactive_regrade_changing_num_tries_finished() {
                 $this->get_tries_remaining_expectation(3));
 
         // Submit the right answer.
-        $this->process_submission(array(
+        $this->process_submission([
             'choice0' => '1',
             'choice1' => '1',
             'choice2' => '0',
             'choice3' => '0',
             'choice4' => '0',
-            '-submit' => '1'
-        ));
+            '-submit' => '1',
+        ]);
 
         // Verify.
         $this->check_current_state(question_state::$gradedright);
@@ -550,6 +555,7 @@ public function test_interactive_regrade_changing_num_tries_finished() {
         $this->check_current_mark(2);
     }
 
+    #[\Override]
     protected function get_contains_num_parts_correct($num) {
         $a = new \stdClass();
         if ($num == 1) {
diff --git a/version.php b/version.php
index 021d7f7..d4133ee 100644
--- a/version.php
+++ b/version.php
@@ -29,10 +29,10 @@
 $plugin->requires  = 2021051700;
 $plugin->component = 'qtype_oumultiresponse';
 $plugin->maturity  = MATURITY_STABLE;
-$plugin->release   = '2.4 for Moodle 3.11+';
+$plugin->release   = '2.5 for Moodle 5.0+';
 
-$plugin->dependencies = array(
+$plugin->dependencies = [
     'qtype_multichoice' => 2020061500,
-);
+];
 
 $plugin->outestssufficient = true;