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:
Diseases that can be transmitted between organisms are  
 (A) infectious. (B) inherited. (C) environmental. (D) congenital.

Ex Output:
A


Ex Input:
As water cools to a temperature of zero degrees Celsius and forms ice, water molecules tend to  
 (A) move farther apart. (B) vibrate rapidly. (C) flow more randomly. (D) gradually expand.

Ex Output:
A


Ex Input:
In winter, the arctic fox has white fur. In summer, its fur changes color to brown and gray. The change in fur color helps the arctic fox to ___.  
 (A) run (B) mate (C) hide (D) hibernate

Ex Output:

C