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: Calcium carbonate (CaCO_{3}) is considered a compound because it is made up of two or more  
 (A) molecules. (B) elements. (C) gases. (D) solids.

Output: B


Input: Consider Input: Soil will pack down over time which decreases the ability of the soil to hold water. Which animals would best help the soil hold water?  
 (A) earthworms making tunnels under the surface (B) cattle making depressions with their hooves (C) horses making trenches when they gallop (D) sheep pulling up plants by their roots

Output: A


Input: Consider Input: A jet plane is moving at a constant velocity on a flat surface. Which forces act against the forward motion of the plane?  
 (A) gravity and engine thrust (B) engine thrust and friction (C) friction and air resistance (D) air resistance and gravity


Output: C