This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
The hormone involved in the regulation of blood pressure is 
Select and explain. 
A. Serotonin, B. Histamine, C. Angiotensin, D. Prostaglandin
C: Angiotensin
Answer: C: Angiotensin 
Explanation: The hormone involved in the regulation of blood pressure is Angiotensin II. Angiotensin II is a powerful vasoconstrictor that increases the total peripheral resistance and decreases Na+ and H2O excretion by kidney, thereby causing an increase in aerial BP. Humoral Regulation of BP Ref: Ganong Medical Physiology 26th edition PGno: 586