I would do a quiz, user override, and give this student a second attempt. Be careful, depending on how you set up the quiz, the student might see which questions on the first attempt they answered correctly.
When giving the student a second attempt, you can decide if you want the highest grade, or average grade to be the student's final grade.
You can also delete the first attempt, which then gives this student a new try.
Or you can tell the student that the questions answered on the first attempt will be carried forward into the second attempt. You would have to do this manually.
Or, you could tell the student "That's it! Be more careful on the next quiz."