Answer: Gas pedal
Explanation: Gas pedal is also known as accelerator pedal.
It is a trigger in an automobile which accelerates the process of fuel combustion in the engine. Automobiles consist of an Internal Combustion engine i.e. the fuel burns inside a closed chamber to generate the energy.
When the gas pedal is triggered the supply of the fuel to the engine increases and the rate of fuel combustion also increases which in turn produces greater power. And we know that power is the rate of doing work or the rate of energy transfer which causes the acceleration in the vehicle.