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.

Ex Input:
A meeting of scientists, called a symposium, occurs every year to share recent research about the atmosphere of Earth. This symposium mainly serves which purpose in science?  
 (A) to test research methods used by other scientists (B) to develop questions about space research (C) to discuss the meaning of new discoveries (D) to explain gas properties to the general public

Ex Output:
C


Ex Input:
Which two behaviors best demonstrate stewardship?  
 (A) reducing consumption, recycling wastes (B) increasing consumption, discarding wastes (C) reducing consumption, discarding wastes (D) increasing consumption, recycling wastes

Ex Output:
A


Ex Input:
Which object in our solar system reflects light and is a satellite that orbits around one planet?  
 (A) Earth (B) Mercury (C) the Sun (D) the Moon

Ex Output:

D