Question

what is the greatest source of indoor air pollution in less - developed countries? air conditioning units poorly ventilated cooking fires

Explanation:

In less - developed countries, many households use traditional cooking methods with open fires or inefficient stoves for cooking. These cooking fires are often poorly ventilated, leading to the release of a large amount of pollutants like particulate matter, carbon monoxide, and other harmful gases into the indoor air. Air - conditioning units are not as prevalent in less - developed countries as in developed ones, and they are not a major source of indoor air pollution in these regions.

Answer:

Poorly ventilated cooking fires