As a student, you are not able to edit or re-do your answer. However, you can ask your teacher to reset your assignment so you are able to redo it. We are working on giving your teacher the possibility to give you multiple attempts to the same question, but at the moment you only have one attempt unless your teacher resets your assignment.
If you want to go an extra step, we recommend that you write down the response you wanted for this question on a paper and share it with your teacher. We are sure s/he will appreciate the effort. Or go ahead and leave a comment; check this article to see how.