The answer is: D - all of the above.
Explanation:
When a voltage source is connected to a circuit, the voltage will cause a uniform flow of charge carriers through that circuit called a current.
Voltage is the pressure from an electrical circuit's power source that pushes charged electrons (current) through a conducting loop, enabling them to do work such as illuminating a light.
In brief, voltage = pressure, and it is measured in volts (V).
