"Correct your answer!"
Translation:תקני את התשובה שלך!
@Zachary Cohen(raulpollos): You are correct that תקן is the masculine singular command, but they probably rejected it because שלכם is masculine plural. Thus you're saying "you fix" to one person while saying "your answer" to multiple people.
I think that it's reasonable to accept your answer, because you might address one individual who represents a group. However, it's also reasonable to reject it because only by matching gender and number of those first and last words is it clear that you recognize the relationship between them.
2020-05-14 rich739183 (edited)