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': 'Ideally Dentist population ration should be \nSelect and explain. \nA. 5.597222222, B. 1:10000, C. 1:20000, D. 1:40000', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]