This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Most common non protein nitrogenous fraction of
blood: 
Select and explain. 
A. Urea, B. Uric acid, C. Urobilinogen, D. Creatinine
C: Urobilinogen
Answer: C: Urobilinogen 
Explanation: None