Students can review their scorecard and regenerate a similar question if they choose. Simply scroll down to the bottom of the student working and find the link 'Practice this problem again'.
The question will be similar in that it will be the same skill, but automatically regenerated numbers. It can be thought of more like a "practice" question.
Attempting these similar problem will not alter the original data. That way, teachers can still identify what the misconceptions students had during the set task.
If you would like to see improvement in the student, we recommend that you duplicate the original task, perhaps edit to just the questions they showed misconceptions, reassign, and have the students attempt those particular questions again.