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: Unknown
[{'content': 'Which of the following is true about an antrochoanal polyp? \nSelect and explain. \nA. Common in adults, B. Commonly Singular, C. Commonly bilateral, D. Is usually allergic', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Commonly Singular Antrochoanal PoIvdEthmoidal PolypCommon in childrenCommon in adultsInfectionAllergySolitaryMultipleUnilateralBilateralMaxillary sinus near the ostiumEthmoidal sinuses, uncinate process, middle turbinate and middle meatusGrows backward to the choanaMostly grow anteriorly and may present at the naresPolypectomy; endoscopic removal orPolypectomyCaldwell-Luc operation if recurrentEndoscopic surgery or ethmoidectomy (Which may be intranasal, extranasal or transantral)", 'role': 'assistant'}]