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
Glue ear - 
Select and explain. 
A. Is painful, B. Is painless, C. Radical mastoidectomy is required, D. NaF is useful
B: Is painless
Answer: B: Is painless 
Explanation: Glue Ear/serous Otitis Media is a painless condition
Ref. Dhingra 5/e, p 72, 6/e, p 64; Current Otolaryngology 2/e, p 658