Can I reset the answer to a quiz question when the learner returns to that slide?

I have a multiple choice question in the middle of my course that is set to 'infinite' attempts. After the user answers the question correctly and continues with the course, they may decide to hit 'back' and navigate back to the quiz question. I want to 'reset' the previously submitted answer so that the user can answer the question again as many times as they like. However, the question is locked and does not allow the user to select a different answer. I have tried adding the 'clear' button and changing the question from 'graded' to 'survey' but neither has worked. Is it possible to reset the quiz question after the user returns to that slide?