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 moon goes through phases as it revolves around Earth. During which phase of the moon would it be possible for a solar eclipse to occur?  
 (A) new moon (B) full moon (C) waning (D) waxing

A: A
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Q: Scientists have studied the specific stages in the life cycle of stars. In which stage do stars spend most of their lifetime?  
 (A) red giant (B) black dwarf (C) white dwarf (D) main sequence

A: D
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Q: Mars is an inner planet and Jupiter is an outer planet. Which best describes the relationship between the two planets?  
 (A) They are made of the same materials. (B) They orbit the Sun in opposite directions. (C) They have the same orbital periods around the Sun. (D) They are located on opposite sides of the asteroid belt.

A:
D
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