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


[Q]: Which of these statements about nonrenewable resources is true?  
 (A) They are inexpensive. (B) They help keep the air clean. (C) They can take millions of years to form. (D) They are used because they are easily removed from the ground.
[A]: C


[Q]: Which tool will best help scientists understand relationships between oceans and climate changes?  
 (A) a computer model (B) a weather balloon (C) a rain gauge (D) radar
[A]:
A