Hint: It is known that the white light has seven colors. When the white light is made to pass through a prism, or when the medium in which the white light travels, changes then it splits into its constituent colors also known as VIBGYOR. This phenomenon is known as dispersion of light.
Complete solution: The amount by which the white light splits into its constituent colors depends on its wavelength and the value of refractive index. Out of the seven colors, violet color has maximum value of refractive index and when the medium through which it travels will change, then its speed will also decrease. All the colors of white light have different wavelengths and their deviation is also different. Also, the violet color has the least wavelength. Therefore when it travels from one medium to another, then it has the maximum value of the angle of incidence and the violet color will deviate the most. But the red color has maximum wavelength so it will deviate the least.
Option B is the right answer.
Note: It is important to remember that the wavelength of a light wave is defined as the distance between two successive crests or two successive troughs of the wave. But wavelength is inversely proportional to the frequency. Therefore, if a light wave has a longer wavelength, then the frequency of the wave will be low. But if the wavelength of the light wave is shorter, the light wave will have a high value of frequency.