Question

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

Explanation:

In less - developed countries, many households rely on traditional cooking methods that use solid fuels (such as wood, coal, dung). These cooking fires are often in poorly ventilated spaces. Poor ventilation means that pollutants like particulate matter, carbon monoxide, and other harmful gases from the burning fuel accumulate indoors. Air - conditioning units are less common in less - developed countries compared to the prevalence of traditional cooking methods. Also, air - conditioning units (when properly maintained) are more about temperature and humidity control rather than being a major source of pollution in the context of indoor air quality in these regions.

Answer:

Poorly ventilated cooking fires.