Which Statement About Capillaries Is True

Which statement about capillaries is true?

A) Capillaries are the principle sites in closed circulatory systems where blood releases oxygen,nutrient molecules,and hormones.
B) Oxygen must diffuse across 2-10 layers of epithelial cells to exit capillaries and reach its target cells.
C) Capillaries are more numerous than arterioles but less numerous than venules.
D) The lumen of capillaries is large enough for 2-10 red blood cells to flow adjacent to one another.
E) Capillaries are only found near specialized brain and lung cells.