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: Pharmacology
[{'content': 'The ratio of the median lethal dose of the median effective dose is the \nSelect and explain. \nA. Morbidity index, B. Moratality index, C. Anesthetic ratio, D. Therapeutic index', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]