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': 'Pulse pressure in severe aortic regurgitation is equal to- \nSelect and explain. \nA. 30-45 mmHg, B. 45-60 mmHg, C. 60-75 mmHg, D. 75-90 mmHg', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]