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.
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Question: 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

Answer: D


Question: Which material is most easily recycled at school?  
 (A) plastic wrap (B) notebook paper (C) ice cream sticks (D) rubber erasers

Answer: B


Question: The egg stage in the life cycle of a bird is most like which phase in the life cycle of certain types of flowers?  
 (A) seed (B) spore (C) pollen (D) immature flower

Answer:
A