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.

Example Input: A student mixes vinegar and baking soda to use in a volcano model. The mixture causes the volcano model to feel cool when it is touched. What energy transformation has taken place?  
 (A) light energy changed to heat energy (B) heat energy changed to chemical energy (C) chemical energy changed to heat energy (D) chemical energy changed to light energy
Example Output: B

Example Input: Which of the following animals is an invertebrate?  
 (A) Squirrel (B) Sea gull (C) Cricket (D) Lizard
Example Output: C

Example Input: Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill?  
 (A) Kinetic energy decreases and potential energy increases. (B) Kinetic energy increases and potential energy decreases. (C) Both potential energy and kinetic energy decrease. (D) Both potential energy and kinetic energy increase.
Example Output:
B