How is a purely electric vehicle different from a vehicle with a combustion engine?

Your answer is correct. Purely electric vehicles differ from combustion engine vehicles mainly because they produce very little engine noise, making them quieter during operation. Additionally, they do not have direct exhaust emissions since they do not burn fuel like combustion engines, which helps reduce air pollution. The option about lower aerodynamic drag is not necessarily true, as this depends on the vehicle's design, not the type of engine. Understanding these differences helps in recognizing the environmental and operational advantages of electric vehicles.