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.

Input: Consider Input: Which statement best describes how birth and death rates compare in a population at carrying capacity?  
 (A) The birth rate is greater than the death rate. (B) The birth rate is less than the death rate. (C) The birth rate is equal to the death rate. (D) The birth rate and the death rate are zero.

Output: C


Input: Consider Input: What happens to the water vapor in an air mass as it ascends?  
 (A) It freezes. (B) It condenses. (C) It vaporizes. (D) It polarizes.

Output: B


Input: Consider Input: When a bird sings, it is most likely singing in order to  
 (A) frighten away other types of birds (B) mark the bird's territory against the same type of bird (C) attract insects (D) wake up other animals


Output: B