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.

Example Input: Which of these best describes wind energy?  
 (A) limited (B) renewable (C) damaging (D) inexpensive
Example Output: B

Example Input: Which characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?  
 (A) refraction (B) reflection (C) conduction (D) amplification
Example Output: B

Example Input: Materials such as carbon and nitrogen go through cycles. The cycling of nitrogen waste materials is mostly dependent upon the role of which factor?  
 (A) atmosphere (B) bacteria (C) sunlight (D) trees
Example Output:
B