This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
A male patient presents with headache , profuse sweating and palpitations with a blood pressure of 180/120 mmHg . The drug of choice would be 
Select and explain. 
A. Nifedipine, B. Labetalol, C. Prazocin, D. Phenoxy benzamine
B: Labetalol
Answer: B: Labetalol 
Explanation: Ref Harrison 19 th ed pg 1627 Symptomatic hypeension with diastolic pressure of 120 suggests a diagnosis of hypeensive emergency . Labetalol (IV) is the drug of choice for management of hypeensive emergency.