**Core Concept**
The portal venous system is a network of veins that carries blood from the gastrointestinal tract, gallbladder, and pancreas to the liver for detoxification and nutrient processing. This system plays a crucial role in the metabolism of nutrients and the removal of waste products.

**Why the Correct Answer is Right**
The correct answer is related to the unique characteristic of the portal venous system, which is that it carries blood from the digestive organs to the liver. This is essential for the liver to detoxify the blood and process nutrients before they are distributed to the rest of the body. The portal venous system is a high-pressure system due to the presence of the hepatic portal vein, which is formed by the confluence of the superior mesenteric vein and the splenic vein.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect because it does not accurately describe a characteristic of the portal venous system.
**Option B:** This option may be incorrect because it does not specifically relate to the portal venous system.
**Option C:** This option is incorrect because it does not accurately describe the function of the portal venous system.

**Clinical Pearl / High-Yield Fact**
The portal venous system is often referred to as the "deoxyribonucleic acid (DNA) of the digestive system" because it carries a high concentration of nutrients and waste products from the digestive organs to the liver for processing.

**Correct Answer:** D.