The correct option is D Gastrointestinal tract to liver
The hepatic portal system is the system of veins consisting of the hepatic portal vein and its capillaries. It is responsible for directing blood from different parts of the gastrointestinal tract to the liver. The system begins with the capillaries and veins of the digestive system. It collects venous blood from the lower esophagus, stomach, duodenum, jejunum, ileum, colon, spleen and delivers it to the liver through the portal vein. So, the correct answer is 'Gastrointestinal tract to liver'.