This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Polyp, Subject name: ENT
[{'content': 'Antrochoanal polyp arise from? \nSelect and explain. \nA. Ethmoid sinus, B. Maxillary sinus, C. Frontal sinus, D. Sphenoid sinus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) Maxillary sinusREF: Dhingras ENT 5th ed p-188, 4th edition page 164See table of "DIFFERENCES BETWEEN ANTROCHOANAL AND ETHMOIDAL POLYP" in ENT December 2009', 'role': 'assistant'}]