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 lists the diameter of the planets in order from smallest to largest?  
 (A) Venus, Earth, Mercury, Mars (B) Earth, Mars, Venus, Mercury (C) Mars, Mercury, Earth, Venus (D) Mercury, Mars, Venus, Earth
Example Output: D

Example Input: About how long is a lunar cycle?  
 (A) 1 day (B) 1 week (C) 28 days (D) 52 weeks
Example Output: C

Example Input: Which is a force that keeps Earth in orbit around the Sun?  
 (A) friction (B) gravity (C) radiation (D) magnetism
Example Output:
B