Answer: b. small intestine.
Step-by-step explanation:
The small intestine is approximately 4.5 meters long in a living person but is 6 meters long at autopsy when the muscles relax. Digestion occurs primarily in the duodenum, which receives the pancreatic juice enzymes. The small intestine provides a large surface area for absorption. Glucose and amino acids from food are absorbed through the small intestine and enter the blood via the hepatic portal vein, going to the liver.