Which type of vehicle does NOT emit harmful emissions during operation?

Zero-emission vehicles are designed to operate without producing harmful emissions during their operation. This typically includes electric vehicles, which run on batteries or hydrogen fuel cell vehicles that use a chemical reaction to generate electricity, producing only water vapor as a byproduct. The absence of an internal combustion engine in zero-emission vehicles means that they do not contribute to air pollution through tailpipe emissions, unlike conventional gasoline and diesel vehicles which release pollutants such as carbon monoxide, nitrogen oxides, and particulate matter during operation.

In contrast, hybrid vehicles do emit some level of emissions, albeit less than conventional gasoline and diesel vehicles, as they combine an internal combustion engine with an electric motor. Therefore, while hybrids are more efficient and environmentally friendly than fully conventional vehicles, they are not categorized as zero-emission.