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 of these is a renewable resource found in Nevada?  
 (A) zinc metal (B) gravel deposits (C) petroleum products (D) geothermal energy

A: D
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Q: Which adaptation helps a bird fly?  
 (A) larger feet (B) bigger eyes (C) longer beaks (D) hollow bones

A: D
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Q: Solids, liquids, and gases are all different states of which of the following?  
 (A) mass (B) matter (C) weight (D) volume

A:
B
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