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
De Musset's sign is seen in 
Select and explain. 
A. Tricuspid regurgitation, B. Mitral stenosis, C. Aortic regurgitation, D. Marfan syndrome
C: Aortic regurgitation
Answer: C: Aortic regurgitation 
Explanation: De Musset's sign - nodding of head with each systole seen in Aortic regurgitation.