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: To study the effect of heat on plant growth, Andy divided ten identical seedlings into groups. She placed one group on a windowsill in the sun and the other group in a dark closet on the cool (north) side of the house. Think about the characteristics of a properly designed scientific experiment. What is wrong with the above experiment?  
 (A) The temperature difference between the two groups was not great enough. (B) The amount of light was different for the two groups. (C) One group of seedlings got less water than the other. (D) Nothing is wrong with the experiment.

A: B
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Q: Different units of measurement are more useful in some settings than in others. Which unit of measurement is most used when comparing distances within the solar system?  
 (A) the mile (B) the kilometer (C) the light year (D) the astronomical unit

A: D
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Q: A student observes a substance that is highly reflective and able to conduct electricity. The substance also has a high melting point. Which is the most likely classification for this substance?  
 (A) salt (B) glass (C) metal (D) plastic

A:
C
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