If a sound wave and a radio wave have with similar wavelength then

b. The frequency of the radio wave will be MUCH HIGHER

The frequency is related to the speed of the wave:

v=fl

or

f=v/l

The speed v of sound is

340 m/s

The speed of radio waves is

3 x 10⁸ m/s.

Let's say the wave length is 2 m. That would make the frequency for sound:

f=340 m/s/2m = 170 Hz.

and for radio waves, that move at the speed of other Electro Magnetic Radiation, a.k.a. light:

f=3x10⁸ m/s / 2 m = 1.5 x 10⁸ Hz.