Consider the following types of vehicles: I. Full battery electric vehicles II. Hydrogen fuel cell vehicles III. Fuel cell-electric hybrid vehicles How many of the above are considered as alternative powertrain vehicles?

Alternative powertrain vehicles are those that do not rely on conventional internal combustion engines running on petrol/diesel. Full battery electric vehicles (BEVs) use electric motors powered by batteries; hydrogen fuel cell vehicles (FCEVs) use hydrogen-powered fuel cells; and fuel cell-electric hybrid vehicles combine fuel cells with battery-electric powertrains. All three qualify as alternative powertrain technologies.