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]: The most significant human-induced impact on Earth's atmosphere comes from the use of which energy resource?  
 (A) flowing water (B) fossil fuels (C) sunlight (D) winds
[A]: B


[Q]: A light-year is a measure of  
 (A) time. (B) energy. (C) distance. (D) direction.
[A]: C


[Q]: Which characteristic do both the Moon and Earth share?  
 (A) They both have rocky surfaces. (B) They both have active volcanoes. (C) They both have similar atmospheres. (D) They both have the same gravitational pull.
[A]:
A