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 teacher breaks a bar of pure copper into two different sized pieces. Which is the most likely difference between the two pieces?  
 (A) mass (B) texture (C) boiling point (D) melting point
answer:
A


question:
Which characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?  
 (A) refraction (B) reflection (C) conduction (D) amplification
answer:
B


question:
What is the primary energy source driving circulation of ocean currents on Earth?  
 (A) geothermal heating (B) planetary rotation (C) solar heating (D) lunar tidal forces
answer:

C