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 scientist is known for his genetics experiments with pea plants?  
 (A) Charles Darwin (B) Gregor Mendel (C) Carolus Linnaeus (D) Robert Hooke
Example Output: B

Example Input: Typically, sedimentary rocks are formed  
 (A) only in erupting volcanoes. (B) only under great pressure and high temperatures. (C) below Earth's surface as magma cools and crystallizes. (D) from materials that settle.
Example Output: D

Example Input: Which of these is the best reason for exercising on space flights?  
 (A) to increase strength for moving around in the cabin (B) to keep from becoming overweight on a space mission (C) to minimize the loss of muscle mass due to microgravity (D) to ensure that bodily fluids do not tend to collect in the feet
Example Output:
C