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: ENT
[{'content': 'Glue ear - \nSelect and explain. \nA. Is painful, B. Is painless, C. Radical mastoidectomy is required, D. NaF is useful', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Glue Ear/serous Otitis Media is a painless condition\nRef. Dhingra 5/e, p 72, 6/e, p 64; Current Otolaryngology 2/e, p 658', 'role': 'assistant'}]