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: When a hammer strikes a nail, the nail  
 (A) exerts balanced forces that helps it from moving. (B) exerts a force equal to the weight of the hammer. (C) exerts an unbalanced force that changes its velocity. (D) exerts an equal and opposite force back on the hammer.

Output: D


Input: Consider Input: Which of the following best represents one particular stage in a life cycle?  
 (A) a fish swimming (B) a seed sprouting (C) a leaf growing (D) a dog eating

Output: B


Input: Consider Input: Skunks spray a strong-smelling liquid to ___.  
 (A) get rid of wastes (B) attract prey (C) defend themselves (D) help nearby plants grow


Output: C