What happens when the engine's idle speed is too high?

What happens when the engine's idle speed is too high?
A)The engine runs faster and consumes more.Correct
B)The engine runs faster and consumes less.
C)It consumes the same as if it were not high.
Idle is the minimum operating speed of the engine when we are not accelerating. It can run faster or slower. The faster the engine runs, the more fuel it will consume; therefore, the slower it runs, the less fuel it consumes.