Answer: The correct answer is that they have the same speed.
Step-by-step explanation:
Electromagnetic waves are defined as the waves which are created by the vibrations between the electric and magnetic field. The two fields propagate perpendicularly to each other.
These waves have certain characteristics including amplitude, frequency and wavelength. So, it is different and characteristic for every electromagnetic waves.
These waves travel with the same speed of light in vacuum. Hence, the correct answer is that they have the same speed.