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
Major poion of coronary blood flow occurs during 
Select and explain. 
A. Systole, B. Diastole, C. Not related to phases, D. It is variable
B: Diastole
Answer: B: Diastole 
Explanation: The pressure inside the left ventricle is slightly higher than in the aoa during systole. Flow occurs in the aeries supplying the subendocardial poion of the left ventricle only during diastole, although the force is sufficiently dissipated in the more superficial poions of the left ventricular myocardium to permit some flow in this region throughout the cardiac cycle.Ref: Ganong&;s Review of medical physiology 25th edition. Page: 611