I think I have managed to make this seem more difficult than it is (which would not be a first).
The user's replies are in the form of radio button clicks. Never, never, never anything more. No text fields. No nothing. They are being tested on their ability to translate English medical terms correctly. This is strictly multiple choice.
It's just that if they choose wrong, I would like to leave the wrong choice up there and have them take another go at it before giving them the next word. And that is the rub.
I just can't figure out a way to give them a second go.
Giving them a new question is pretty straightforward.
I'm not interested in their score either. They can keep score themselves.
Sorry for all the bother.