This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
[{'content': 'X-ray showing air column between soft tissue mass and posterior wall of the nasopharynx is suggestive of? \nSelect and explain. \nA. Ethmoidal polyp, B. Antrochoanal polyp, C. Nasal myiasis, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In the case of antrochoanal polyps, X-ray of paranasal air sinuses may show opacity of the involved antrum. X-ray(lateral view) of soft tissue nasopharynx, reveals a globular swelling in the postnasal space. It is differentiated from angiofibroma by the presence of a column of air behind the polyp. Ref - PL DHINGRA diseases of ear nose and throat, 7th edition, page no 193', 'role': 'assistant'}]