This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiac disorders, Subject name: Pathology
Most common cause of mitral stenosis is: 
Select and explain. 
A. Rheumatic hea disease, B. Infective-endocarditis, C. Diabetes mellitus, D. Congenital
A: Rheumatic hea disease
Answer: A: Rheumatic hea disease 
Explanation: The most frequent causes of the major functional valvular lesions are: Aoic stenosis: calcification and sclerosis of anatomically normal or congenitally bicuspid aoic valves Aoic insufficiency: dilation of the ascending aoa, often secondary to hypeension and/or aging Mitral stenosis: rheumatic hea disease Mitral insufficiency: myxomatous degeneration (mitral valve prolapse)