According to the sentences shared from The Destructors, the word that best describes Trevor is <u>peculiar</u>.
From those sentences we can't tell that Trevor's silence is because he is cautious or introspective. Nothing in those lines tells us any other thing for us to understand that he is one of those two things.
On the other hand, we can know from the sentence "When he said 'Trevor' it was a statement of a fact, not as it would have been with the others a statement of shame or defiance" that he didn't mean to be threatening, so the choice left is C.
Peculiar, as an adjective, means that someone clearly distinguishes from the rest for some personal characteristic. Trevor's attitude is clearly different from the rest of the gang and it is something that distinguishes him.
"They provide a framework that enables wider engagement in the whole political process. Through these political parties, anyone who is an American citizen is able to run for office, and anyone can vote and express their preference for any one party."
