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: Prolonged exercise stimulates muscle cells to absorb sugar from the blood. This mechanism reduces stress placed on the body by signaling the body to produce  
 (A) insulin. (B) lipids. (C) hemoglobin. (D) hydrochloric acid.

Output: A


Input: Consider Input: A student mixes a teaspoon of sugar in a large glass of water. What happens to the sugar when it is mixed with the water?  
 (A) It boils. (B) It melts. (C) It dissolves. (D) It evaporates.


Output: C