instruction:
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.
question:
A student tosses a ball into the air. Which force causes the ball to fall back to the ground?  
 (A) gravity (B) magnetism (C) mechanical (D) friction
answer:
A


question:
Which of the following statements best explains why earthquakes occur more frequently in California than in Massachusetts?  
 (A) The rock found in California is igneous, but the rock found in Massachusetts is sedimentary. (B) California is located on the boundary of two crustal plates, but Massachusetts is not. (C) The rock under California is soft, but the rock under Massachusetts is hard. (D) California is located on a continental plate, but Massachusetts is not.
answer:
B


question:
An Earth year is the length of time it takes for  
 (A) Earth to rotate once on its axis (B) the Moon to revolve once around Earth (C) the Sun to revolve once around Earth (D) Earth to revolve once around the Sun
answer:

D