Answer:
Speed
Step-by-step explanation:
When waves travel in different mediums then due to change in the speed of the wave the path of the wave will change.
Initially wave is travelling in the given direction with some speed "v"
now when the medium of the wave will change then it will change the speed as we know that
now due to this change in the refractive index of the speed and hence the wavelength will change in different mediums
So here correct answer will be
D) Speed