Concept:Car exhaust can contain toxic gases due to incomplete combustion of fuel.
Explanation:When petrol or diesel burns in a car engine, the oxygen supply is often not enough for complete burning.
This causes incomplete combustion of the fuel.
Incomplete combustion produces carbon monoxide,
CO, instead of carbon dioxide,
CO2.
Carbon monoxide is a hazardous, poisonous gas.
It is colorless, odorless, and tasteless.
It combines strongly with hemoglobin in the blood, reducing oxygen transport in the body.
This can cause serious health effects or even death.
Therefore, among the options,
CO is the hazardous substance emitted from car exhaust fumes.
Answer:Option B (
CO)