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.
--------
Question: While conducting an experiment on gravity, what will be needed to ensure the safety of students?  
 (A) quiet zones (B) drop zones (C) heavy objects (D) frictionless surfaces

Answer: B


Question: Which physical structure would best help a bear to survive a winter in New York State?  
 (A) big ears (B) black nose (C) thick fur (D) brown eyes

Answer: C


Question: The smallest particle of an element is  
 (A) an atom. (B) a mixture. (C) a molecule. (D) a compound.

Answer:
A