A submitted answer can only be edited if a response is still In Review.
If you need to edit an answer, the submission is still in the In Review status, and the deadline has not passed, you can always delete your response and resubmit.
To delete a response, go to your In Review tab from the Questions dashboard, and look for the orange trash icon. If the question is still open, you can click the icon to delete the response you need to edit and resubmit.

