From the capillaries of the abdominal organs and hind limbs, blood flows to the from the capillaries of the abdominal organs and hind limbs, blood flows to the right atrium left atrium aorta capillaries of the lungs inferior vena cava

The correct answer is "inferior vena cava".

The venous drainage from the abdominal organs such as the spleen, stomach, intestines, omentum, and mesentery are the splenic vein and superior mesenteric vein which will eventually form the portal vein which will drain into the inferior vena cava. The venous drainage from the hind limbs will form external iliac veins wherein the internal iliac veins will join to form the common iliac vein. The left and right common iliac vein will then form the inferior vena cava.