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: Cells come in two basic types, prokaryotic and eukaryotic. Which cell structure is found in both prokaryotic and eukaryotic cells?  
 (A) vacuole (B) nucleoid (C) mitochondrion (D) cytoplasm

A: D
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Q: Which energy source is nonrenewable?  
 (A) sunlight (B) biomass (C) wind (D) fossil fuel

A: D
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Q: In which way is a prokaryotic cell different from a eukaryotic cell?  
 (A) A prokaryotic cell is larger. (B) A prokaryotic cell has no nucleus. (C) A prokaryotic cell can reproduce itself. (D) A prokaryotic cell has a cell membrane.

A:
B
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