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.

Input: Consider Input: When pressure is released along a fault line, the energy produced spreads as mechanical waves in the form of an earthquake. The mechanical waves transferred to the air become  
 (A) sound. (B) electricity. (C) light. (D) heat.

Output: A


Input: Consider Input: A student examines a new watch design. The watch has a small solar cell on its face. The main function of the solar cell is to  
 (A) reduce the cost of the watch. (B) provide an energy source for the watch. (C) make the watch more attractive. (D) stop the watch from speeding up.

Output: B


Input: Consider Input: Base your answer on the information below and on your knowledge of science. A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change?  
 (A) The baseball strikes the roof. (B) The roof of the car dents. (C) The paint cracks and chips. (D) The exposed metal rusts.


Output: D