Four ways the atmosphere can affect light

Four ways atmosphere can affect light is  1. Light is sent back into Space this is reflection. 
2.Refraction: Light bends in the atmsophere finally reaching the ground. This is our ainstay of Solar energy on ground. 
3. Scattering: The wavelength gets altered and distributed all around at different wavlengths, causing the 'blue' colour that defines 'sky'. 
4. Absorption: The light photons simply vanish into the matter (as energy) heating up GHGs, converted by Chrophyll of plants for food, getting converted to Vitamin D by human bodies & so on. Don't hold atmosphere responsible for these, except as enabler by sending down light. 

Iwould say the answer would be b