Multiple choice

Name the gas which under normal conditions produces pollution in the atmosphere.

  1. Carbon monoxide (CO)

  2. Carbon dioxide (CO2)

  3. Nitrogen (N2)

  4. Oxygen (O2)

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carbon monoxide is a toxic gas produced by incomplete combustion, acting as a direct pollutant. While CO2 is a greenhouse gas, CO is considered a primary pollutant under normal conditions.