suggestion: when the correct answer is already selected in the first attempt, the second verification should be disabled, by mistake in questionnaire M3.02 I marked the answer of question 5 in question 4 which was initially correct in the first attempt.
I am not sure that the FUN platform allows for such tweaking. But I agree that it would be more intuitive as a user-facing interface.
ping @MarieCollin @lfarhi
FYI I tagged this fun-mooc-feed-back.
General tip: I think a screenshot would help a lot to make the problem more clear 
I also edited the title of the post to be more explicit but feel free to improve it since I am not sure I understand the problem 
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