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: All of the different organisms interacting in a pond make up  
 (A) a community (B) a population (C) the water cycle (D) the habitat

A: A
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Q: When a person speaks, the type of wave produced can be described as all these except  
 (A) transverse. (B) mechanical. (C) compression. (D) longitudinal.

A: A
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Q: The hormone insulin is secreted by the pancreas. Which activity is most likely to trigger an increase in the levels of insulin circulating in the blood?  
 (A) driving (B) eating (C) jogging (D) sleeping

A:
B
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