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: Unknown
[{'content': "Highest mortality in pregnancy - \nSelect and explain. \nA. Eissenmenger syndrome, B. Fallot's tetrology, C. Coarctation of aorta, D. Marfan's syndrome", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: A', 'role': 'assistant'}]