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: Gynaecology & Obstetrics
In valvular heart disease complicating pregnancy the following statements are true except: 
Select and explain. 
A. A closed mitral valvotomy can be carried out if symptoms of mitral stenosis are severe, B. Open heart surgery is associated with a reduction in fetal loss, C. Mitral regurgitation is usually well tolerated, D. A maternal mortality of 15% has been reported in women with critical aortic stenosis
B: Open heart surgery is associated with a reduction in fetal loss
Answer: B: Open heart surgery is associated with a reduction in fetal loss 
Explanation: None