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': 'During extraction of a maxillary molar a root tip is left in the maxillary sinus. The treatment of choice is: \nSelect and explain. \nA. Perform Caldwell-Luc to remove the tip, B. Perform hemi maxillectomy, C. Enlarge opening in the socket area, D. No treatment indicated', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]