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': 'The branch of biostatistics which deals with the births, deaths and marriage is called as: \nSelect and explain. \nA. Health, B. Medical, C. Demography, D. Vital', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]