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: 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: In the human body, which system functions primarily to defend the body against disease?  
 (A) digestive (B) immune (C) nervous (D) respiratory

Output: B


Input: Consider Input: Use the information to answer the question. Over the last 150 years, the use of fossil fuels has increased, resulting in more carbon dioxide and other greenhouse gases in the atmosphere. Some scientists think that these atmospheric gases will result in global warming. Scientists have recorded data on global temperature changes and have predicted possible changes in sea level that may affect Maryland residents. Using fossil fuels in the United States will most likely contribute to rising sea levels globally by  
 (A) increasing oxygen levels (B) decreasing oxygen levels (C) increasing carbon dioxide levels (D) decreasing carbon dioxide levels


Output: C