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:
Some birds fly south in the fall and return in the spring. This is an example of  
 (A) migration (B) camouflage (C) hibernation (D) growth

Ex Output:
A


Ex Input:
Which two life processes occur in both plants and humans?  
 (A) growing and reproducing (B) germinating and making food (C) growing and making food (D) germinating and reproducing

Ex Output:
A


Ex Input:
The central nervous system consists of two parts: the brain and the  
 (A) senses. (B) organs. (C) muscles. (D) spinal cord.

Ex Output:

D