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]: When a person speaks, the type of wave produced can be described as all these except  
 (A) transverse. (B) mechanical. (C) compression. (D) longitudinal.
[EX A]: A

[EX Q]: Which step will most likely ensure that the results of an investigation are valid?  
 (A) using a computer to graph results (B) verifying that results match the original hypothesis (C) comparing the results with those of other scientists (D) eliminating any results that appear to be abnormal
[EX A]: C

[EX Q]: The Heliocentric Theory, as supported by Copernicus, revolutionized scientific theories regarding  
 (A) the life cycle. (B) the water cycle. (C) the solar system. (D) the immune system.
[EX A]:
C