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: The systems of the human body work together. Which system works with the skeletal system by pulling on the bones to create movement?  
 (A) digestive (B) circulatory (C) muscular (D) nervous

A: C
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Q: Which group of organisms can make food by a process called chemosynthesis?  
 (A) scavengers (B) producers (C) consumers (D) decomposers

A: B
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Q: A complete fossil has been found of a type of bird that cannot be identified. What can most likely be determined about the bird from the fossil?  
 (A) The bird lived for a very short time. (B) The bird lived in a dry environment. (C) The bird existed at one time but is now extinct. (D) The bird was not well preserved during the process of fossilization.

A:
C
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