Hi! Could you check my answer to this question?

Q.) In "The Most Dangerous Game", the character of Zaroff serves as a(n) __________ to the protagonist, sharply contrasting Rainsford's personality.

This wasn't a multiple-choice answer. The question has us type it in ourselves, so I can't give you a list of potential answers. However, I believe that the answer is either "foil" or "antagonist" (I choose the former if you want me to pick one.)

Could you let me know if either answer would be acceptable? Thank you so much.

Also! I know many people don't share their gratitude for the tutors on this website, so I just wanted to say... Thank you for all you guys do!! Every answer has been explained to me in full, which has helped me to actually learn the material. Online school has been extremely difficult for me since I have extreme concentration issues, and I just don't learn with the teaching method my school's curriculum uses. This site has been a godsend for me ever since I started. So thank you. I really appreciate all the hard work you do for us, even after people slander your names and write hateful responses in the "answers" pod. We the students really don't deserve any of you. :)

I agree with you that “foil” is the best word to describe Zaroff.

Thank you for your kind words.
Thank you, also, for using this website correctly: for learning!