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: 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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Q: A hearing aid is a small device that contains an amplifier, a battery, a microphone, and a speaker. Which part of a hearing aid functions to detect sounds in the user's environment?  
 (A) the amplifier (B) the battery (C) the microphone (D) the speaker

A: C
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Q: Which wind-water interaction is responsible for cycling nutrient-rich waters from the ocean floor to the sea surface?  
 (A) upwelling (B) storm surge (C) downwelling (D) surface currents

A:
A
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