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': 'Hiatus semilunaris is present in - \nSelect and explain. \nA. Superior meatus, B. Middle meatus, C. Inferior meatus, D. sphenoethmoidal recess', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Important structures of middle meatus are :-\n\n\nHiatus semilunaris, \nEthmoidal infundibulum,\nAnterior & posterior fontanelle,\nUncinate process,\nBulla ethmoidalis.', 'role': 'assistant'}]