Question panels have been designed to allow either single or multiple attempts at answering. If only one attempt at answering is allowed, a popup will appear when you first select Check Answer:
If you are happy with your answer and wish to continue, select Commit. If you wish to review or edit your answer, select Cancel. Once you have committed an answer, you will no longer be able to change it. If multiple attempts at answering the question are allowed, no popup will appear and you will be able to answer the question as many times as you’d like.