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
Prominent x descent in JVP is seen in all except 
Select and explain. 
A. Cardiac tamponade, B. Atrial septal defect, C. Tricuspid regurgitation, D. Constrictive pericarditis
C: Tricuspid regurgitation
Answer: C: Tricuspid regurgitation 
Explanation: In tricuspid regurgitation x descent is absent. X descent is due to atrial relaxation during atrial diastole.