The correct answer is C. The number of waves passing through a point in one second.
An alternating current (AC) is an electric current that reverses its direction periodically. The frequency of an AC is the number of times per second that the current reverses its direction. It is measured in hertz (Hz).
The frequency of an AC is determined by the speed at which the alternator runs. The alternator is a device that converts mechanical energy into electrical energy. It does this by rotating a coil of wire inside a magnetic field. The faster the alternator rotates, the higher the frequency of the AC.
The number of cycles generated in one minute is not a measure of frequency. A cycle is one complete cycle of an AC wave. The number of cycles generated in one minute is equal to the frequency of the AC multiplied by 60.
The number of electrons passing through a point in one second is not a measure of frequency. The number of electrons passing through a point in one second is equal to the current multiplied by the time.
Therefore, the correct answer is C. The number of waves passing through a point in one second.