11. Why is the velocity of blood flow the lowest in capillaries?
(A) The capillary walls are too thin to maintain the velocity of blood flow in capillaries.
(B) Capillaries are far from the heart, and blood flow slows as the distance from the heart increases.
(C) The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate.
(D) The total surface area of the capillaries is larger than the total surface area of the arterioles.
(E) The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the rightventricle.