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: Cell division is necessary for an organism to  
 (A) obtain nutrients. (B) grow and reproduce. (C) make proteins. (D) conserve matter and energy.
Example Output: B

Example Input: Sam looks into a fish pond and points at a goldfish. Sam's grandfather looks where Sam is pointing and tells Sam that the fish is actually in a different location. Which property of light explains why Sam's grandfather is correct?  
 (A) reflection (B) refraction (C) diffraction (D) absorption
Example Output: B

Example Input: Which of the following is closest to the percentage of the total water on earth that is freshwater?  
 (A) 100% (B) 90% (C) 70% (D) 3%
Example Output:
D