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
Balloon valvotomy is successful in all of the following cases except – 
Select and explain. 
A. Congenital pulmonary stenosis, B. Calcified mitral stenosis, C. Mitral stenosis is pregnancy, D. Congenital aortic stenosis
B: Calcified mitral stenosis
Answer: B: Calcified mitral stenosis 
Explanation: It is indicated in MS without calcification.