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 main reason for replacing premature loss of primary anterior teeth \nSelect and explain. \nA. Form and function, B. Speech and esthetics, C. Space maintenance, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]