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 involves the greatest variety of cell types?  
 (A) a tissue (B) an organ (C) an organ system (D) an organism

Output: D


Input: Consider Input: The change in fur color of the Arctic hare from brown in the summer to white in the winter is an example of  
 (A) mimicry. (B) heredity. (C) diversity. (D) camouflage.

Output: D


Input: Consider Input: Which activity is necessary for humans to maintain good health?  
 (A) reading (B) resting (C) driving (D) talking


Output: B