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': 'Rubber dam was introduced by \nSelect and explain. \nA. Tomy Hanks, B. S.C. Barnum, C. Hedstorm, D. G.V. Black', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]