Alright, so the first statement is a Sufficient & Necessary statement.
Let's diagram:
"A poem is any work of art that exploits some of the musical characteristics of language, such as meter, rhythm, euphony, and rhyme."
We know that "all" is an indicator word for the sufficient condition. Thus, any synonyms that means "all" in a sentence will also point to the sufficient condition. In this case, "any" means "all." The sentence is saying that all works of art that exploit some of the musical characteristics of language will be considered a poem.
So, we diagram like so:
P1: WoAEL ==> P Not P ==> not WoAEL
So, if we have a novel that exploits meter and rhyme while standing as a work of art, i.e. "WoAEL," then it is both a novel and a poem, according to "P1."
So, answer choice (C) must be true.
Hope that clears thing up! Please let us know if you have any other questions.