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': 'A 5-year-old child with recurrent sinusitis, cause is: \nSelect and explain. \nA. Adenoids, B. Angiofibroma, C. Nasal carcinoma, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) Adenoids(Ref. Scott Brown, Vol 2; 286)Because of nasal obstruction the child can have recurrent sinusitis. Angiofibroma and nasopharyngeal carcinoma are not seen at this age.', 'role': 'assistant'}]