Answer:
1.25
Step-by-step explanation:
Index of refraction also known as refractive index determines the speed of the light in the particular material. The light can bend towards the normal or away from the normal in the particular media.
Different objects have different index of refraction. The amount of the light refracted by the media can be calculated by the help of the refractive index. The refractive index of an actual material is 1.25. The refractive index of the media depends on the density of the substance.
Thus, the correct answer is option (D).