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]: If a student playing the drums hits the drums with greater force, the sound would be  
 (A) quieter. (B) louder. (C) lower in pitch. (D) higher in pitch.
[EX A]: B

[EX Q]: The systems of the human body work together. Which system works with the skeletal system by pulling on the bones to create movement?  
 (A) digestive (B) circulatory (C) muscular (D) nervous
[EX A]: C

[EX Q]: Many sports stadiums use grass, but some use fake grass called artificial turf. Artificial turf is made of fibers that look like real grass. In which way is this technology most likely beneficial?  
 (A) It uses less water. (B) It produces more heat. (C) It releases less moisture. (D) It absorbs more carbon dioxide.
[EX A]:
A