It is very easy, especially when you break down the words. Let's see what the prefix of the word 'antagonist' is. The prefix is "An" which is a short form of 'anti.' Meaning against something or bad. The opposite of antagonist is protagonist (pro is the prefix, meaning good) Therefore, antagonist is against a protagonist. Which makes a antagonist a bad person or villain. And the protagonist becomes the hero or good guy. The answer is C)