It’s either b or C! I hope that all helps
The phrase <em>the antique fire truck </em>is used as a complete subject, because you are including all of these words to form a subject, so it cannot be a simple one (just one word). It isn't a compound subject either, because that would be two or more words connected with a conjunction <em>and, </em>or some other one.
The conflict, hes tired of waiting for this mysterious "she" and he would rather leave and feel grown as much as he is.
