This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anaesthesia, Subject name: Anaesthesia
[{'content': 'Highest MAC is of Which inhalational agent- \nSelect and explain. \nA. Xenon, B. Halothane, C. Sevoflurane, D. Isoflurane', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Minimum alveolar concentration is defined as the alveolar concentration of an inhaled anesthetic agent that prevents movement in 50% of patients in response to a standardized surgical stimulus. Low MAC - High potency MAC values of adult Halothane: 0.75 Sevoflurane: 2.0 Isoflurane: 1.2 Desflurane: 6.0 Enflurane: 1.7 Xenon: 70 N2O: 104', 'role': 'assistant'}]