C: demonstrate that Washington was an important figure in history
B. Winnowing wind because of the repetition of 'w'
The best answer for the way to focus on the topic of memoir would be D. I hope that this 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.
