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': 'Antrum of Highmore is \nSelect and explain. \nA. Maxillary, B. Ethmoid, C. Sphenoid, D. Frontal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Antrum of Highmore is maxillary sinus.\nIt is the largest of paranasal sinuses.', 'role': 'assistant'}]