Question

which of the following is the most common source of indoor air pollutants in less - developed countries? carbon monoxide from vehicles cleaning solvents formaldehyde from building materials poorly ventilated cooking fires

Explanation:

In less - developed countries, many households rely on solid fuels like wood, charcoal, and dung for cooking. These cooking fires often occur in poorly - ventilated spaces, releasing large amounts of pollutants such as particulate matter, carbon monoxide, and unburned hydrocarbons. Vehicle - related carbon monoxide is more of an outdoor or urban traffic - related issue. Cleaning solvents and formaldehyde from building materials are less prevalent compared to cooking fires as sources of indoor air pollution in less - developed countries due to lower usage and exposure levels.

Answer:

poorly ventilated cooking fires