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: A bright object with a long tail of glowing gases is in orbit around the Sun. This object is most likely  
 (A) a planet (B) a star (C) an asteroid (D) a comet

A: D
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Q: Which of the following climates has cold winters and hot summers?  
 (A) polar (B) subtropical (C) temperate (D) tropical

A: C
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Q: Students visit an aquarium and watch how an octopus behaves in its tank. Which behavior did the octopus most likely learn from its aquarium environment?  
 (A) waiting to be fed at the aquarium door (B) catching food using its arms (C) being more active at night (D) hiding behind rocks

A:
A
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