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: Surgery
[{'content': 'Placement of very sharp pointed instrument into the periodontium to extrude tooth out of the socket, this is called: \nSelect and explain. \nA. Lever principle., B. Wedge principle., C. Wheel and axle principle., D. None.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]