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.

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

One substance found on Earth is more stable as an elemental gas than as part of a solid compound. As a result, this substance is very abundant in the atmosphere. Which substance exhibits these traits?  
 (A) argon (B) chlorine (C) nitrogen (D) oxygen
C

A student finds a bottle that is labeled with a long chemical name. What is the best way for the student to learn more about the chemical properties of this substance?  
 (A) shake the container vigorously (B) smell a very small amount of it (C) look up the name in a science book (D) test a small amount to see if it feels slippery

C