Which of the following represents the distribution of blood supply to the heart by the coronary arteries?
a) 90% by the right coronary artery (RCA) and 10% by the circumflex artery
b) 10% by the right coronary artery (RCA) and 90% by the circumflex artery
c) 90% by the left coronary artery (LCA) and 10% by the circumflex artery
d) 10% by the left coronary artery (LCA) and 90% by the circumflex artery