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.

Example Input: Which tool would be best to use for counting the number of legs on an ant?  
 (A) ruler (B) hand lens (C) calculator (D) microscope
Example Output: B

Example Input: Because copper is a metal, it is  
 (A) liquid at room temperature (B) nonreactive with other substances (C) a poor conductor of electricity (D) a good conductor of heat
Example Output: D

Example Input: Where is most of the mass of the atom located?  
 (A) in the protons (B) in the nucleus (C) in the neutrons (D) in the electrons
Example Output:
B