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: What happens when water flows over a rock for a long period of time?  
 (A) erosion (B) flooding (C) breakage (D) evaporation

Output: A


Input: Consider Input: Which unit is used to indicate the amount of energy in food?  
 (A) ounce (B) degree (C) calorie (D) gram

Output: C


Input: Consider Input: Land subsidence (ground level dropping) is most likely an indication that  
 (A) sediments are being deposited. (B) water is being polluted. (C) rocks are being weathered. (D) ground water is being depleted.


Output: D