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:
About how long is a lunar cycle?  
 (A) 1 day (B) 1 week (C) 28 days (D) 52 weeks

Ex Output:
C


Ex Input:
In order to maintain good health, humans should  
 (A) eat foods high in fat (B) exercise regularly (C) drink alcohol often (D) smoke tobacco occasionally

Ex Output:
B


Ex Input:
Which of these best demonstrates the characteristics of science?  
 (A) One student lifts a rock and skips it across a stream. (B) One student thinks about rocks and writes down his opinion. (C) Two students study a rock and then compare their observations. (D) Two students remove rocks from a garden and then plant flowers.

Ex Output:

C