This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': 'Largest sinus: \nSelect and explain. \nA. Frontal sinus, B. Maxillary sinus, C. Ethmoidal sinus, D. Aphenoid sinus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Maxillary sinusRef: Dhingra 5th Ed. / 203-204Maxillary sinus is largest sinus with volume of around 15 cc.', 'role': 'assistant'}]