You are given a science question (easy-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.

[Q]: Large amounts of industrial gases are released into the atmosphere every day. What happens to those gases?  
 (A) They are broken down by ultraviolet light from the Sun. (B) They are converted into nitrogen and oxygen. (C) They rise through the atmosphere and go into outer space. (D) They remain in the atmosphere for long periods of time.
[A]: D


[Q]: In an accurate diagram of the solar system, which object would be shown closest to Earth?  
 (A) the Moon (B) the asteroid belt (C) Mars (D) Saturn
[A]: A


[Q]: Over a long period of time, helpful variations in a species replace the unfavorable ones. This change can lead to  
 (A) fossilization. (B) evolution. (C) geographic isolation. (D) genetic mutations.
[A]:
B