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: Jeannie put her soccer ball on the ground on the side of a hill. What force acted on the soccer ball to make it roll down the hill?  
 (A) gravity (B) electricity (C) friction (D) magnetism
Example Output: A

Example Input: Which property of air does a barometer measure?  
 (A) speed (B) pressure (C) humidity (D) temperature
Example Output: B

Example Input: Phobos is one of two large objects that orbit the planet Mars. Because Phobos orbits Mars, Phobos should be classified as which type of body?  
 (A) asteroid (B) moon (C) comet (D) meteor
Example Output:
B