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': 'Treatment of choice for perforation in pars flaccida of the tympanic membrane with cholesteatoma is - \nSelect and explain. \nA. Myringoplasty, B. MRM-Modified Radical Mastoidectomy, C. Antibiotics, D. Radical mastoidectomy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: CSOM is of Two Types', 'role': 'assistant'}]