A. can be crossed out because the Parthenon was made out of marble. Concrete was not available back then in the BC's.
B. is an opinion, therefore it would not be necessarily correct. It depends on each person's background knowledge of Greek temples, so I would not choose that answer.
C. I would choose this choice. The front of the Monticello resembles much like the front of a Greek temple with the popular marble columns.
D. is also an opinion. It depends on a person's definition of "simple". In terms of geometry, however, I would say it is simple. Temples are typically rectangular rooms, and a rectangle is a simple polygon. Greek temples are also famous for rows of columns. Hope this helps!