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:
Which occurs as a result of Earth's tilt on its rotating axis?  
 (A) movement of the tides (B) prevalent or trade winds (C) seasonal changes in the climate (D) light and dark changes of day and night

Ex Output:
C


Ex Input:
Bridge inspectors have determined that a bridge is unsafe. Which of the following is the BEST design process the company should use to correct the problem?  
 (A) identify the problem-repair the bridge-plan for the repair (B) plan for the repair-repair the bridge-identify the problem (C) plan for the repair-identify the problem-repair the bridge (D) identify the problem-plan for the repair-repair the bridge

Ex Output:
D


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