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: Medicine
[{'content': 'Heart failure with preserved ejection fraction - \nSelect and explain. \nA. Dilated cardiomyopathy, B. Restrictive cardiomyopathy, C. MI, D. Hypertension', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]