How to edit question from quiz results
First, locate and open the quiz with the attempt or question that needs to be corrected. Then, click the attempts number or the results tab. Find the attempt with the question you wish to correct and click the start/end time or the score to open the quiz.
To change the grade for just this attempt, click Make comment or override grade.
To permanently change all attempts, find the incorrect question and click the edit icon.
Once you have finished editing the question, click Save changes at the bottom of the page. To implement the changes for all existing attempts, click Regrade at the top of the page.