The major contributor to carbon monoxide emissions in metropolitan areas of India is

The transport sector is the chief source of carbon monoxide in Indian metropolitan areas.

The industrial sector adds pollutants but is not the main carbon monoxide source in cities.

Domestic sources contribute far less carbon monoxide than vehicles.

The agriculture sector is a minor contributor in dense urban areas.

Incomplete combustion of petrol and diesel in vehicle engines releases carbon monoxide.

Heavy traffic and congestion make road transport the dominant urban source.