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: Anaesthesia
[{'content': 'Drug used to prolong action of LA in Hypeensive pts? \nSelect and explain. \nA. Clonidine, B. Felypressin, C. Dexmeditomidate, D. Noradrenalin', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b'.e., Felypressin", 'role': 'assistant'}]