If we install a spoiler on our vehicle, what will happen?

If we install a spoiler on our vehicle, what will happen?
A)The vehicle will consume more fuel.Correct
B)The vehicle will consume less fuel.
C)Fuel consumption will not be altered.
Any element that affects the aerodynamics of the vehicle, not being expressly designed for that purpose, will entail a variation in the aerodynamic drag coefficient, consequently increasing fuel consumption.