Argon, which comprises almost 1 percent of the atmosphere, is approximately 27 times more abundant than CO2 but does not contribute to global warming. Which explanation accounts for this fact?
a. Single atoms do not have bonds, therefore do not vibrate.
b. Argon's vibrational energy is not excited by infrared radiation.
c. Argon atoms are concentrated too high in the troposphere to interact with the earth's radiant energy.
d. Argon is not an anthropogenic pollutant.

B. Argon's vibrational energy is not excited by infrared radiation.

Explanation:

The property of carbon dioxide to get excited by infrared electromagnetic radiation is what qualifies it as a greenhouse gas. When infrared from the earth's surface is reflecting back to space, some of the radiation is absorbed and remitted by the carbon-dioxide molecules in the atmosphere. This causes a phenomenon called greenhouse effect that causes the atmosphere to be relatively warmer. The more the carbon dioxide molecules the more the greenhouse effect.