B; As far as the relation between humans and the environment, it is obvious how much they relied on it. Not only as a food source, but for economic growth and sustainability as well. The other answers make valid points but in the context of this question, the only one that even mentions the relation is B.
The Saudi Arabia politics are take place in the context of a totalitarian absolute monarchy with some Islamic (Wahhabi Islam) lines, and the King is both the Saudi Arabia's head of state and absolute monarch (i.e. he is the head of government). The King also serves as the head of the Saudi royal family, the House of Saud, which is also why the country bears the name that it has.
I believe the answer is C! The opposite sides are parallel