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: Surgery
[{'content': 'Dicrotic nature of aoic notch is lost in? \nSelect and explain. \nA. Aoic Stenosis, B. Aoic Regurgitation, C. PDA, D. Aeriosclerosis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Aoic Stenosis REF: Harrison's 17th ed chapter 220 Anacrotic pulse with a slow initial upstroke, the peak is close to S2; these features suggest fixed left ventricular outflow obstruction, such as occurs with valvular aoic stenosis", 'role': 'assistant'}]