This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
Dicrotic notch is due to closure of 
Select and explain. 
A. Aoic valve, B. Mitral valve, C. pulmonary, D. Tricuspid valve
A: Aoic valve
Answer: A: Aoic valve 
Explanation: Dicrotic notch is due to backflow of blood in the aoa at the beginning of diastole.It marks the end of ventricular systole. Reference:Textbook of medical physiology Geetha,2nd edition,page no:187.