What is the unit of normalized frequency?

Hertz
Meter/sec
Coulombs
It is a dimensionless quantity

The correct answer is D. Normalized frequency is a dimensionless quantity. It is defined as the ratio of the frequency of a wave to a reference frequency. The reference frequency is usually chosen to be the frequency of a sine wave with a wavelength of 1 meter.

Hertz (Hz) is the unit of frequency. It is defined as the number of cycles per second. Meter/sec is the unit of speed. Coulombs is the unit of charge.

A dimensionless quantity is a quantity that does not have any units. It is a pure number.