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: Pharmacology
Reduces blood pressure primarily by directly decreasing hea rate alone - 
Select and explain. 
A. Propranolol, B. Prazosin, C. Alpha methyl dopa, D. Nitroprusside sodium
A: Propranolol
Answer: A: Propranolol 
Explanation: Ans. is 'a' i.e., Propranolol o Methyldopa is useful in the treatment of mild to moderately severe hypeension. It lowers blood pressure chiefly by reducing peripheral vascular resistance, with a variable reduction in hea rate and cardiac output. o Prazosin and nitroprusside are vasodilators and produce reflex tachycardia instead of causing bradycardia. o Propranolol is a non selective beta blocker and acts mainly by decreasing hea rate.