This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, Subject name: ENT
[{'content': 'Xray showing air column between soft tissue mass and posterior wall of nasopharynx is suggestive of - \nSelect and explain. \nA. Ethmoidal polyp, B. Antrochoanal polyp, C. Nasalmyiasis, D. None of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Antrochoanal polyp o On xray.antrochoanal polyp appears as a soft tissue density and shows a column of air between the soft tissue mass and posterior wall of nasopharynx.", 'role': 'assistant'}]