This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anaesthesia
[{'content': 'Least MAC is of which inhalational agent \nSelect and explain. \nA. Xeonon, B. Halothane, C. Sevoflurane, D. Isoflurane', 'role': 'user'}, {'content': "Answer: B \nExplanation: Agent MAC(%)EtherHalothaneEnfluraneIsofluraneDesfluraneSevofluraneNitrous oxide 1.90.751.681.26.02.0105(Refer: Morgan and Mikhail's Clinical Anaesthesiology, 5th edition, pg no. 167-169)", 'role': 'assistant'}]