TASK DEFINITION: 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.
PROBLEM: 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

SOLUTION: A

PROBLEM: One important use of coal is to produce energy for homes. Coal can be burned and converted to  
 (A) wind energy. (B) nuclear energy. (C) electrical energy. (D) solar energy.

SOLUTION: C

PROBLEM: An example of a renewable resource is  
 (A) oil. (B) coal. (C) wood. (D) natural gas.

SOLUTION:
C