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]: Which system of the human body provides protection to most of the major organs?  
 (A) skeletal system (B) circulatory system (C) respiratory system (D) muscular system
[EX A]: A

[EX Q]: The molecule ATP is composed of elements commonly found in organic molecules. Which of the following is one of these elements?  
 (A) aluminum (B) calcium (C) phosphorus (D) tin
[EX A]: C

[EX Q]: Energy from the Sun changes ocean water to a gas. This sentence describes which step in the water cycle?  
 (A) condensation (B) evaporation (C) precipitation (D) runoff
[EX A]:
B