Final answer:
The propagation speed of a beam in a medium does not change with frequency. The speed is constant for a given medium, while frequency and wavelength are inversely related to maintain this constant speed.
Step-by-step explanation:
If the frequency of the beam increases, the propagation speed in the media will not change. The correct answer is C) Not change. The speed of propagation is constant in a given medium and is determined by the medium's physical properties, such as density and elasticity. When the frequency increases, the wavelength decreases to maintain the constant speed, according to the wave equation v = f λ where v is the speed of the wave, f is the frequency, and λ is the wavelength.
It's also important to note that for electromagnetic waves in a vacuum, the speed of propagation is always the speed of light, which is constant and does not depend on the frequency or wavelength. This is stated by the principle c = 1/√(με), where c is the speed of light, μ is the permeability of free space, and ε is the permittivity of free space.