The correct answer is: C. 30 to 300 MHz.
The high frequency band is a radio frequency band that ranges from 30 to 300 MHz. It is used for a variety of applications, including television broadcasting, amateur radio, and two-way radio.
The high frequency band is characterized by its long wavelengths. This makes it well-suited for applications that require long-range communication, such as television broadcasting and amateur radio. However, the long wavelengths also make the high frequency band susceptible to interference from objects in the environment, such as buildings and trees.
The high frequency band is also known as the VHF band (very high frequency).
Option A: 100 kHz is in the low frequency band.
Option B: 1 GHz is in the microwave band.
Option D: 3 to 30 MHz is in the medium frequency band.