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: Which of these will most likely harm a habitat?  
 (A) planting trees (B) water pollution (C) rainfall (D) sunlight

Output: B


Input: Consider Input: Which gas accounts for the largest percentage of greenhouse gases in the atmosphere?  
 (A) carbon monoxide (B) carbon dioxide (C) nitrous oxide (D) water vapor


Output: D