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 relationship between ticks and a dog can best be described as  
 (A) mutualism. (B) competition. (C) parasitism. (D) commensalism.
[EX A]: C

[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]: Which statement explains what will most likely happen to the hydrosphere in an area where air temperatures increase?  
 (A) Earthquake intensity will decrease. (B) Mountain formation will decrease. (C) Rock weathering will increase. (D) Evaporation will increase.
[EX A]:
D