Will gice which is not a method of decreasing air pollution? putting scrubbers on smokestacksputting catalyic converts in carsburning unleaded gasolineusing cars that get lower gas mileage

The answer is; burning unleaded gasoline

Unleaded gasoline does not reduce carbon emissions. The lead was added to fuel ideally for vehicles to reduce the knocking of engines. Lead in its chemical structure also increased fuel octane levels. When lead was discovered to be a neurotoxin, it was banned as an additive in fuel in most countries.