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 pot is heated on a stove. Which process causes the metal handle of the pot to also become hot?  
 (A) combustion (B) convection (C) radiation (D) conduction

A: D
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Q: Which object works best when reflecting light?  
 (A) mirror (B) camera (C) binoculars (D) eyeglasses

A: A
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Q: Some immune cells are actively involved in ingesting, destroying, and presenting invading microbial antigens on their surface to stimulate other cells to produce antibodies. Which of these cells is responsible for initiating such an immune response?  
 (A) mast cells (B) phagocytes (C) B-lymphocytes (D) T-lymphocytes

A:
B
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