Answer:
C. industry, transportation, and energy production
Step-by-step explanation:
Gaseous pollutants are air pollutants. More completely, we can consider that gaseous pollutants are particles of different sizes in the form of vapors that invade the atmosphere mixing with the air and being breathable by living beings, causing several problems. The main promoters of this type of pollution in the USA are the industry, transport and energy production, which pollute the air, mainly, through the burning of fossil fuels, allowing their harmful substances to be thrown into the atmosphere.