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': "Teeth which can't be used as abutment: \nSelect and explain. \nA. Endodontically treated teeth, B. Pulp capped teeth., C. Both, D. None", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]