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': "A composite index combining indicators representing longevity, knowledge and income is \nSelect and explain. \nA. Physical quality of life index, B. Human development index, C. Sullivan's index, D. Human poverty index", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]