This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidneys and Body Fluids, Subject name: Physiology
Physiologically inactive form is 
Select and explain. 
A. Angiotensin I, B. Angiotensin II, C. Angiotensin III, D. Angiotensin IV
A: Angiotensin I
Answer: A: Angiotensin I 
Explanation: Ans. (a) Angiotensin I(Ref: Ganong, 25th ed/p.696)Angiotensin II & III got physiological activitiesAngiotensin I is only the precursor of Angiotensin II