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': "De Musset's sign is seen in \nSelect and explain. \nA. Tricuspid regurgitation, B. Mitral stenosis, C. Aortic regurgitation, D. Marfan syndrome", 'role': 'user'}, {'content': "Answer: C \nExplanation: De Musset's sign - nodding of head with each systole seen in Aortic regurgitation.", 'role': 'assistant'}]