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 best describes a characteristic of the jet stream?  
 (A) It forms a boundary between a cold air mass and a warm air mass. (B) It creates the high winds around the eye of a hurricane. (C) It forces the hot air along the equator to rise to areas in North America. (D) It causes high pressure air masses to rotate clockwise.
Example Output: A

Example Input: What property is the same for each atom of an element?  
 (A) energy (B) mass number (C) atomic number (D) number of neutrons
Example Output: C

Example Input: Physical features help animals survive. Which statement best describes physical adaptations that occur through natural selection in changing environments?  
 (A) They result in population decline. (B) They are all observable in the fossil record. (C) They occur slowly over long periods of time. (D) They are more likely to be observed in plants.
Example Output:
C