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': 'The adult maxillary air sinus always lies directly above the following teeth: \nSelect and explain. \nA. Incisors, B. Incisors and canine, C. Premolars, D. Molars', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]