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 energy source is considered nonrenewable?  
 (A) moving water (B) fossil fuel (C) wind (D) biomass

A: B
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Q: A student conducts an investigation. In order to make a valid conclusion, she must  
 (A) have a testable hypothesis. (B) place the data in a graph. (C) use the best technology. (D) test multiple variables.

A: A
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Q: From Earth, the Sun appears brighter than any other star because the Sun is the  
 (A) newest star. (B) largest star. (C) hottest star. (D) closest star.

A:
D
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