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
Which cardiovascular condition during pregnancy has the highest maternal moality rate ? 
Select and explain. 
A. Primary pulmonary hypeension, B. Marfan's syndrome, C. Coarctation of the aoa, D. Mitral stenosis
A: Primary pulmonary hypeension
Answer: A: Primary pulmonary hypeension 
Explanation: Primary pulmonary hypeension