Physics lenses/critical angle question need asap

The answer should be B.

There are 2 conditions for total internal reflection:

For this question, light is travelling from glass to air, so the first condition is fulfilled. Yet, the angle of incidence is only 30°, which is less than the critical angle. Therefore, total internal reflection will not occur.

Instead, there will be refraction. Light ray bends away from normal when it is travelling to a less dense object, thus having a greater angle of refraction than the angle of incidence.

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.

well clustered together.

points close on a scatter diagram