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': 'Reaming action of the reamer is \nSelect and explain. \nA. Pushing regenerating, B. Pushing, rotating & regenerating, C. Pushing & pulling, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]