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: Physiology
Pressure-Volume loop of cardiac cycle is shown below. What does point C represent? 
Select and explain. 
A. Mitral valve opens, B. Mitral valve closes, C. Aortic valve opens, D. Aortic valve closes
C: Aortic valve opens
Answer: C: Aortic valve opens 
Explanation: At point C, Ventricular pressure becomes more than aortic pressure. Hence, aortic valve opens.