TASK DEFINITION: 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.
PROBLEM: What property is the same for each atom of an element?  
 (A) energy (B) mass number (C) atomic number (D) number of neutrons

SOLUTION: C

PROBLEM: Which of these statements about nonrenewable resources is true?  
 (A) They are inexpensive. (B) They help keep the air clean. (C) They can take millions of years to form. (D) They are used because they are easily removed from the ground.

SOLUTION: C

PROBLEM: Which statement describes the location of our Sun in the universe?  
 (A) Our Sun orbits Earth in the Andromeda galaxy. (B) Our Sun orbits Earth in the Milky Way galaxy. (C) Our Sun is the center of a solar system in the Milky Way galaxy. (D) Our Sun is the center of a solar system in the Andromeda galaxy.

SOLUTION:
C