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': 'Cutting cone is \nSelect and explain. \nA. Leading edge of osteoblasts, B. Leading edge of osteoclasts, C. Trailing edge of osteoblast, D. Trailing edge of osteoclasts', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]