You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

After a soccer game, Brittany sat under a fan because she was hot. Under the fan, she felt cooler than before. Which explains why Brittany felt cooler under the fan?
(A) Air moving under the fan is cooler than air that is still. (B) The evaporation of sweat absorbs heat from the skin. (C) Water vapor from the fan condenses on the skin. (D) The fan speeds convection currents in the air.
B

Rat snakes, Elaphe obsoleta, are a species made of many distinct populations in different areas. Each of the populations has different markings and colorings. Where would rat snakes most likely be gray?
(A) in a forest (B) in a swamp (C) in a gravel pit (D) in a corn field
C

Which is the best unit to measure distances between Earth and other solar systems in the universe?
(A) miles (B) kilometers (C) light years (D) astronomical units
C