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:
Photosynthesis is the process that converts carbon dioxide and water into  
 (A) carbon and oxygen. (B) sugar and hydrogen. (C) sugar and oxygen. (D) nitrogen and carbon.

Ex Output:
C


Ex Input:
If you breathe on a mirror, part of the mirror clouds up. What are you actually seeing when you see the mirror cloud up?  
 (A) Water droplets that formed from cooled water vapor in your breath (B) Carbon dioxide that you are breathing out from your lungs (C) Oxygen that you are breathing out from your lungs (D) Cooled nitrogen in the air around you

Ex Output:
A


Ex Input:
Stretching is considered an important step before engaging in sports. In an investigation to see whether stretching before physical exertion reduces sports injuries, who would the control group most likely be?  
 (A) athletes who stretch before working out (B) non-athletes who stretch before working out (C) athletes who do not stretch before working out (D) non-athletes who do not stretch before working out

Ex Output:

C