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]: A student placed a small chip of limestone into a hydrochloric acid solution, and carbon dioxide gas was released. The carbon dioxide provided evidence that   
 (A) only a physical change occurred. (B) a chemical change occurred. (C) only a loss of mass occurred. (D) the formation of an element occurred.
[A]: B


[Q]: Which of these is a renewable resource found in Nevada?  
 (A) zinc metal (B) gravel deposits (C) petroleum products (D) geothermal energy
[A]: D


[Q]: Clownfish take shelter in the tentacles of sea anemones and keep sea anemones clean. Which type of relationship does this represent?  
 (A) parasitism (B) commensalism (C) mutualism (D) neutralism
[A]:
C