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
Kussumaul's sign is not seen in - 
Select and explain. 
A. Restrictive cardiomyopathy, B. Constrictive pericarditis, C. Cardiac tamponade, D. RV infarct
C: Cardiac tamponade
Answer: C: Cardiac tamponade 
Explanation: None