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.
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Question: Which force produces energy as heat?  
 (A) pull (B) gravity (C) friction (D) magnetic

Answer: C


Question: Russell wants to observe changes in nature over the next few months. What can a thermometer help Russell investigate?  
 (A) rainfall amounts each week (B) tiny organisms in pond water (C) the high temperatures each day (D) the amount of growth in a plant

Answer: C


Question: Which of the following has the greatest effect on the ability of soil to hold water?  
 (A) the age of the soil particles (B) the size of the soil particles (C) the color of the soil particles (D) the luster of the soil particles

Answer:
B