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.

[EX Q]: The energy that is stored in food originally comes from  
 (A) air (B) soil (C) sunlight (D) water
[EX A]: C

[EX Q]: Which is the most important safety measure to follow when using an acid in a classroom laboratory?  
 (A) wearing protective clothing and goggles (B) keeping the window open (C) closing the door to the hall (D) using bright fluorescent lights
[EX A]: A

[EX Q]: A scientist puts more food than a lab rat can eat in each of 100 cages containing lab rats. She surveys the mass of food each rat eats in one day. To determine the difference between the largest and smallest masses of food eaten, she should find her data's   
 (A) mean. (B) range. (C) mode. (D) median.
[EX A]:
B