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]: What gas in the air do we need to breathe in order to live?  
 (A) nitrogen (B) oxygen (C) carbon dioxide (D) hydrogen (E) water vapor
[A]: B


[Q]: In 2004, Maryland recycled more than 35% of all of the waste the state produced. Which of these benefits does recycling provide to Maryland?  
 (A) fewer wild animals (B) decreased farm crops (C) less trash sent to landfills (D) decreased use of electricity
[A]: C


[Q]: Which of the following best explains why the Sun appears to move across the sky every day?  
 (A) The Sun rotates on its axis. (B) Earth rotates on its axis. (C) The Sun orbits around Earth. (D) Earth orbits around the Sun.
[A]:
B