How does the body regulate the distribution of oxygen and glucose to different body tissues?

A. By changing aortic blood pressure and thus the velocity of blood flow in capillaries.
B. Using valves in veins, which close due to backpressure from the column of blood above them.
C. Using valves found inside arterioles near capillaries.
D. By constricting smooth muscle throughout the capillaries. Via relaxation/constriction of pre-capillary sphincters.