Living Organisms Use Nitrogen to Make Proteins and DNA, So

Living organisms use nitrogen to make proteins and DNA, so how does that nitrogen eventually get back to the atmosphere in the nitrogen cycle?

A) Exhalation
B) Denitrifying bacteria producing nitrates
C) Denitrifying bacteria producing N₂
D) Nitrogen is 79% of the atmosphere, so while it does cycle around, the amount living things contribute is negligible.
E) It dissolves in water and then evaporates back to the atmosphere.