A portal system is one in which

Options

A. Avein starts from an organ and ends up in heart.
B. An artery breaks up in an organ and restarts by the union of its capillaries.
C. The blood from the gut is brought into the kindley before it is poured into posterior vena cava.
D. A vein breaks up in an organ into capillaries and re-starts by their union as a new nein in the same organ.

Answer

D