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]: 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
[A]: B


[Q]: Which of the following climates has cold winters and hot summers?  
 (A) polar (B) subtropical (C) temperate (D) tropical
[A]: C


[Q]: Glaciers cover about 10% of the total land area on Earth. The role of glaciers in the water cycle is to  
 (A) filter salt water (B) store fresh water (C) move liquid water (D) precipitate solid water
[A]:
B