Final answer:
Nitrogen, the gas that makes up about 78% of Earth's atmosphere, does not significantly interact with visible or infrared radiation, making it nearly transparent to infrared frequencies, unlike Carbon Dioxide, Water Vapor, and to a lesser extent Oxygen.
Step-by-step explanation:
The atmospheric gas molecule that is not significantly affected by visible or infrared radiation is Nitrogen (A). Unlike Carbon Dioxide (C), Water Vapor (D), and to a lesser extent Oxygen (B), Nitrogen does not absorb infrared radiation in any significant way. Carbon Dioxide and Water Vapor, in particular, are very effective at absorbing infrared radiation and play a major role in the Earth's greenhouse effect, contributing to global warming.
Conversely, Nitrogen, which makes up about 78% of Earth's atmosphere, has a very limited spectrum of electromagnetic radiation that it can absorb due to its diatomic molecule (N₂) structure, which has very few energy states that can be excited by infrared photons. This difference in molecular interaction with radiation results in Nitrogen being nearly transparent to infrared frequencies.