This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
&;V' wave in JVP is due to 
Select and explain. 
A. Atrial contraction, B. Mitral valve closure, C. Atrial relaxation, D. Tricuspid valve closure
D: Tricuspid valve closure
Answer: D: Tricuspid valve closure 
Explanation: The V wave mirrors the rise in atrial pressure before the tricuspid valve opens during diastole.Ref: Ganong&;s Review of medical physiology, 25th edition.Pg no. 542