Answer:
C. "She should quote the second sentence directly, because it establishes important supporting evidence in a unique way."
Explanation:
I think this one is correct, however I am not positive, it's really just a guess. The first sentence is common knowledge and you shouldn't need to add what the readers already know if it's the main idea. The second sentence isn't necessarily common knowledge and should always be cited.
Hope this helped, let me know if it's right or not.
Cent is not a human, so its not a people noun, and because it does not start with a capital letter or specify a singular place or thing, it is an object noun
D. I believe the answer is D