Sunsets Are Red Because

Sunsets are red because

A) sunlight must pass through more atmosphere, and this scatters more light at red wavelengths than bluer wavelengths.
B) the cooler atmosphere in the evening absorbs more blue light.
C) sunlight must pass through more atmosphere, and this scatters even more light at bluer wavelengths, transmitting mostly red light.
D) the Sun emits more red light when it's setting.
E) none of the above