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: Pediatrics
[{'content': 'Balloon valvotomv is successful in all of the following cases except- \nSelect and explain. \nA. Congenital pulmonary stenosis, B. Calcified mitral stenosis, C. Mitral stenosis is pregnancy, D. Congenital aoic stenosis', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Calcified mitral stenosis It is indicated in MS without calcification.", 'role': 'assistant'}]