The correct answer is C. Watt.
A watt is a unit of power in the International System of Units (SI). It is defined as one joule of energy per second. Power is the rate at which energy is transferred or converted. In the case of electricity, power is the rate at which electrical energy is converted into other forms of energy, such as heat, light, or mechanical work.
The other options are incorrect. A volt is a unit of electric potential or electromotive force. A joule is a unit of energy. An ampere is a unit of electric current.
Electric power is calculated by multiplying the voltage and the current. The formula for power is P = V Ã I, where P is the power in watts, V is the voltage in volts, and I is the current in amperes.
For example, if a light bulb has a voltage of 120 volts and a current of 0.5 amperes, then its power is 60 watts.