What causes different colors to appear in the sky?

a. the absorption of light by air molecules
b. the reflection of light by bodies of water
c. the greenhouse effect in earth’s atmosphere
d. the scattering and reflection of light by dust particles

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim