Ammonia is a nitrogenous waste product of protein metabolism, and is harmful especially in high concentrations in the human body. Urea cycle is a means to detoxify and to prevent the accumulation of ammonia in the body by converting it to urea, and eventually excreted in the urine. How many moles of nitrogen enter the urea cycle in every turn?"
A.
0
B.
1
C.
2
D.
3
E.
6