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.

Q: Which organisms contribute most to the decomposition of dead organisms?  
 (A) snakes (B) viruses (C) insects (D) bacteria

A: D
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Q: Which involves the greatest variety of cell types?  
 (A) a tissue (B) an organ (C) an organ system (D) an organism

A: D
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Q: A company that makes fences started using a new material instead of wood. The new material will last longer than wood. What is the most likely benefit of the new material?  
 (A) The new material will keep people safe. (B) The new material will keep pets contained. (C) The new material can make a yard attractive. (D) The new material can save money on replacements.

A:
D
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