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': 'The recommended clamp for class-V tooth preparation is \nSelect and explain. \nA. No.213, B. No.212, C. No.123, D. No.122', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]