You are given a science question (hard-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: Which animal is preparing for a seasonal change in the environment?  
 (A) a bat flying at night (B) a deer drinking water (C) an owl eating a mouse (D) a squirrel storing nuts

Answer: D


Question: As a car burns fuel, a transformation from chemical to mechanical energy takes place. What is the most likely result of the fuel burning?  
 (A) The matter that makes up the car increases. (B) The amount of useful energy decreases. (C) The efficiency of the car increases. (D) The amount of heat energy decreases.

Answer: B


Question: A ball is thrown downward onto a concrete floor and bounces upward. What supplies the upward force that makes the ball bounce?  
 (A) the floor (B) the pull of gravity (C) the air friction on the ball (D) the person that throws the ball

Answer:
A