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 of articulator was given by: \nSelect and explain. \nA. R.E. Hall, B. Monsoon, C. WGA Bonwill, D. House', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]