The shells of a certain species of marine snail are highly variable, with some snail shells being solid colors and others being striped. which condition of natural selection is this most related to? a. artificial variation b. environmental variation c. genetic variation d. no variation

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.