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: ENT
[{'content': 'In Caldwell- Luc operation the nasoantral window is made through- \nSelect and explain. \nA. Superior meatus, B. Inferior meatus, C. Middle meatus, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Caldwell-Luc operation is a process of opening the maxillary antrum through canine fossa by sublabial approach and dealing with the pathology inside the antrum.\nIn this surgery, antrum is reached through an incision in gingivolabial sulcus (from lateral incisor to 2nd molar) and then opening of antrum in this area.\nDuring the surgery a nose-antral window is made through the inferior meatus so that after the surgery, packing of sinus can be removed through this window.', 'role': 'assistant'}]