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: Anatomy
[{'content': 'Posterior ethmoid sinus opens in which meatus? \nSelect and explain. \nA. Superior, B. Middle, C. Inferior, D. Spenoethmoidal recess', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Superior", 'role': 'assistant'}]