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 is most likely a genetic adaptation of desert plants to survive the hot, dry climate conditions?  
 (A) thin bark (B) waxy leaves (C) leaves that remain all year (D) flowers that bloom all year

Output: B


Input: Consider Input: In the United States, which is responsible for ensuring the safety of the country's drinking water?  
 (A) Environmental Protection Agency (EPA) (B) Food and Drug Administration (FDA) (C) National Oceanic and Atmospheric Administration (NOAA) (D) Center for Disease Control (CDC)


Output: A