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 which of the following heart diseases is materanl mortality during pregnancy found to be the highest: 
Select and explain. 
A. Coarctation of aorta, B. Eisenmenger syndrome, C. AS, D. MS
B: Eisenmenger syndrome
Answer: B: Eisenmenger syndrome 
Explanation: None