Answer:
C. All waves have the same speed.
Step-by-step explanation:
Wave equation is given as;
V = fλ
where;
V is the speed of the wave
f is the frequency of the wave
λ is the wavelength
The speed of the wave depends on both wavelength and frequency
The speed of the electromagnetic waves in a vacuum is 3 x 10⁸ m/s, this also the speed of light which is constant for all electromagnetic waves.
Therefore, the correct option is "C"
C. All waves have the same speed.