8 files declare their use of QuizQuestionResponse in Quiz 8.4

ClozeResponse.php in question_types/cloze/lib/Drupal/cloze/ClozeResponse.php

DDLinesResponse.php in question_types/quiz_ddlines/lib/Drupal/quiz_ddlines/DDLinesResponse.php

LongAnswerResponse.php in question_types/long_answer/lib/Drupal/long_answer/LongAnswerResponse.php

MatchingResponse.php in question_types/matching/lib/Drupal/matching/MatchingResponse.php

MultichoiceResponse.php in question_types/multichoice/lib/Drupal/multichoice/MultichoiceResponse.php

ScaleResponse.php in question_types/scale/lib/Drupal/scale/ScaleResponse.php

The main classes for the short answer response.

ShortAnswerResponse.php in question_types/short_answer/lib/Drupal/short_answer/ShortAnswerResponse.php

The main classes for the short answer response.

TrueFalseResponse.php in question_types/truefalse/lib/Drupal/truefalse/TrueFalseResponse.php