Answer:
a)supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
Step-by-step explanation:
Supercharging is the process of supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere.
By doing this , it increases the power out put and increases the brake thermal efficiency of the engine.It also increases the volumetric efficiency of the engine.
So the our option a is right.