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: Dental
[{'content': 'Crude mortality rate is \nSelect and explain. \nA. Per 100, B. Per 1000, C. Per 10000, D. Per 100000', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]