"사과를 젓가락으로 자르세요."
Translation:Cut the apple with chopsticks.
It ends with a "-세요", so it's polite. The only difference with my answer (which turns out to be wrong) and that with the correct one is the word "please" that I placed at the beginning of the sentence since it's polite. I hope this would be resolved and in the future answers similar to mine would be accepted as correct.
If you think your answer is correct just report it. No one actually reads these comments