The speed of the wave depends on what?

A. The properties of the medium through which the wave travels

B. The wavelength of the wave

C. The frequency of the wave

D. both the wavelength and frequency of the wave

The speed of a mechanical wave depends on the mechanical properties

of the medium through which the wave is traveling.

The speed of an electromagnetic wave depends on the electrical properties

of the medium through which the wave is traveling.

It's pretty well unanimous for choice A.