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: Ophthalmology
[{'content': 'When performing a DCR, the osteum is created at the level of \nSelect and explain. \nA. Superior turbinate, B. Middle turbinate, C. Inferior turbinate, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Osteum is created at the level of middle turbinate.', 'role': 'assistant'}]