TASK DEFINITION: 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.
PROBLEM: You wish to closely observe a small insect. Which tool is the best to use?  
 (A) a balance (B) a test tube (C) a telescope (D) a magnifying glass

SOLUTION: D

PROBLEM: Which material is the best conductor of electricity?  
 (A) Wood (B) Metal (C) Stone (D) Plastic

SOLUTION: B

PROBLEM: Which tool is most responsible for preventing future pandemics of smallpox?  
 (A) worldwide vaccination for smallpox (B) global education about smallpox (C) better worldwide urban sanitation (D) improved global quarantine facilities

SOLUTION:
A