Hint: The angle of deviation is the angle that the emergent ray makes with the direction of the incident ray. When a ray is made to pass from one medium to another medium it creates an angle between the direction of the refracted ray and the direction of the incident ray.
Complete step to step solution: Whenever light passes from one medium to another, the path/direction of the incident light ray changes while going from one medium to another. The path of the emergent ray is different from the path of the incident ray. Both the incident and emergent rays make some angle between them. This angle is what we call the angle of deviation. Glass, Prism, and water are some of the everyday examples where we can observe this difference in the angle of deviation.
Following are the factors on which the angle of deviation depend, a) The angle of incidence b) The refracting angle of the prism c) Refractive index of the material used in the prism d) The wavelength of the light ray Since the angle of deviation is calculated using the angle of incidence ray, the angle of deviation depends on the angle of incidence.
The Refractive index of the prism is the ratio of the speed of light in a vacuum divided by the velocity of light in the medium. Now since the frequency of light remains unchanged irrespective of the medium hence the wavelength of light changes in order to account for the change in the speed of light in the medium.
Therefore, Option (D) is the correct answer.
Additional information: Refractive index of light in water is more than the refractive index of light in air. This implies that light travels faster in the air than in water. Also, the speed of light can be highly reduced using semiconductors.
Note: When the value of the refractive index for a medium is higher than the speed of light in that medium is slower. Do remember that the angle of deviation also depends on the wavelength of light although it is not mentioned in the given options.