Question

is a deadly, colorless, odorless gas that is a by - product of incomplete combustion.
sulphur
cadmium
hydrogen peroxide
carbon monoxide

Explanation:

Carbon monoxide is a gas formed during incomplete combustion. It is colorless and odorless, which makes it dangerous as it can be inhaled without detection. Sulfur is a solid non - metal, cadmium is a metal, and hydrogen peroxide is a liquid.

Answer:

Carbon Monoxide