reviewing quizzes showing correct answers

HI, can you tell me how, when a final module quiz is reviewed by the learner, they can see what the correct answers were?  I don't want to put messages after each question telling the correct answer, I'd like that, once the person finishes, they can go back through the quiz and see what the right answers were. 

currently, when a learner goes back through a quiz, it shows which questions they answered incorrectly, but not what the correct answers should have been; in particular, one slide with a matching activity.

I"ll attach the project, thanks so much