This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
[{'content': 'Arrange following inhalational anesthetic agents according to increasing MAC values i) Isoflurane ii) Desflurane iii) Sevoflurane iv) Halothane \nSelect and explain. \nA. (iv), (i), (iii), (ii), B. (iv), (iii), (i), (ii), C. (ii), (iv), (iii), (i), D. (i), (ii), (iii), (iv)', 'role': 'user'}, {'content': 'Answer: A \nExplanation: MAC: Minimum alveolar concentration of inhalational agent required to produce no movement on surgical stimulus in 50% of test patients. Eg: N2O - 104 Halothane - 0.75 Isoflurane - 1.28 Sevoflurane- 2 Desflurane- 6 Less MAC- high potency High MAC- low potency Most potent inhalational agent- Methoxyflurane Least potent inhalational agent- N2O', 'role': 'assistant'}]