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': 'Spherical theory is proposed by \nSelect and explain. \nA. Bonwill, B. Monson, C. Hall, D. Hanau', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]