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 substance do all living things require to survive?  
 (A) blood (B) water (C) carbon dioxide (D) organic soil
Example Output: B

Example Input: A delta at the mouth of a river is the direct result of  
 (A) runoff from sewage. (B) deposition of sediment. (C) an ancient glacier that passed through. (D) an underground river flowing to the ocean.
Example Output: B

Example Input: Which statement best describes why the Moon is visible from Earth?  
 (A) The Moon reflects light from other planets. (B) The Moon reflects light from the Sun. (C) Light is produced by the Moon. (D) Light from Earth illuminates the Moon.
Example Output:
B