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.

[Q]: 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
[A]: A


[Q]: A boy pulls a sweater off over his head. His hair is attracted to the sweater due to  
 (A) a magnetic force (B) a heat transfer (C) a chemical change (D) an electrical charge
[A]: D


[Q]: The National Aeronautics and Space Administration (NASA) is the agency responsible for the space program in the United States. What was the goal of NASA's Apollo program?  
 (A) to search for life on planets other than Earth (B) to land on a planet in another solar system (C) to determine the composition the Sun (D) to send a human to land on the Moon
[A]:
D