For a ray of light to suffer total internal reflection it has to pass from :

Answer: Option C

Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. This can only occur where light travels from a medium with a higher [n1=higher refractive index] to one with a lower refractive index [n2=lower refractive index]. Total internal reflection can be seen at the air-water boundary.