Answer:
Water Vapor
Step-by-step explanation:
Hydrogen fuel cell powered car are one of the efforts being done to reduce the vehicular emissions. In these cars, hydrogen gas stored in particular conditions are used to generate electricity which powers the motor of the car.
Hydrogen is burnt with oxygen and in this process water vapors are emitted. No greenhouse or other harmful gases are emitted out of it. It is an alternative with zero emission in our environment. Looking at the current state of pollution all over the world and depleting fossil fuels, it is a very good alternative for future.