The S.I unit of frequency is____________.

Option A

The hertz (symbol: Hz) is the derived unit of frequency in the International system of unit (SI) and is defined as one  cycle per second. It is named after Heinrich Rudolf Hertz. the first person to provide conclusive proof of the existence of electro magnetic wave. Hertz are commonly expressed in multiples: kilohertz (10³ Hz, kHz), megahertz (10⁶ Hz, MHz), gigahertz (10⁹ Hz, GHz), terahertz (10¹² Hz, THz), petahertz (10¹⁵ Hz, PHz), exahertz (10¹⁸ Hz, EHz), and zettahertz (10²¹ Hz, ZHz)