what is the greatest source of indoor air pollution in less - developed countries? air conditioning units…

Brief Explanations:

In less - developed countries, many households rely on traditional cooking methods using solid fuels like wood, charcoal, or dung. These cooking fires are often in poorly ventilated spaces. Air - conditioning units are less common in such settings due to cost and infrastructure limitations. Poorly ventilated cooking fires release a significant amount of pollutants (such as particulate matter, carbon monoxide, etc.) into the indoor air.

Answer:

Poorly ventilated cooking fires