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: The Sun is classified as  
 (A) an organism (B) a decomposer (C) a star (D) a planet
Example Output: C

Example Input: Eyeglasses help a nearsighted person see as a result of  
 (A) absorption. (B) diffraction. (C) reflection. (D) refraction.
Example Output: D

Example Input: A student is given a mixture of gravel and sand and instructed to separate them. Which tool should the student use to best complete this task?  
 (A) a scale and weights (B) a magnet (C) a sieve (D) a battery and wire
Example Output:
C