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.

Example Input: Why should plants be included in investigations about the water cycle?  
 (A) Plants speed up the water cycle by removing carbon from the air. (B) Plants start the water cycle when they make water in photosynthesis. (C) Plants are part of the water cycle through the process of transpiration. (D) Plants stop the water cycle because they absorb it and stop the flow to streams.
Example Output: C

Example Input: India is in the Northern Hemisphere and Australia is in the Southern Hemisphere. In June, it is summer in India and winter in Australia. What is the main reason the seasons are opposite in the two countries?  
 (A) because Earth is tilted on its axis (B) because the Sun rotates on its axis (C) because Earth revolves around the Sun (D) because of the distance between the countries
Example Output: A

Example Input: A ball is tossed up in the air and it comes back down. The ball comes back down because of  
 (A) gravity (B) friction (C) erosion (D) magnetism
Example Output:
A