This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular Disorders, Subject name: Gynaecology & Obstetrics
Heart disease in pregnancy, most common - 
Select and explain. 
A. ASD, B. MS, C. VSD, D. MR
B: MS
Answer: B: MS 
Explanation: Ans. is 'b' i.e., MS "Commonest cardiac lesions are of rheumatic origin followed by congenital ones.""Rheumatic valvular leasion predominantly includes mitral stenosis (MS) "