40 points
which of these compounds are a source of nitrogen for animals
a) nitrates
b0 proteins
c) nitrites
d) ammonia

The answer to your question is: Proteins

Explanation:

Ammonia, nitrites and nitrates are part of the Nitrogen cycle where plants absorb nitrogen, when animals eat vegetables, adquiere nitrogen as proteins.

A) nitrates  

B) proteins  This is the correct answer.

C) nitrites

D) ammonia

a, i am pretty sure.

answer transpiration;