**Core Concept**
The liver receives its blood supply from two main sources: the hepatic artery and the portal vein. The hepatic artery supplies oxygenated blood from the aorta, while the portal vein carries nutrient-rich, deoxygenated blood from the digestive organs.

**Why the Correct Answer is Right**
The correct answer reflects the actual blood supply to the liver, with the portal vein contributing approximately 80% of the liver's blood supply and the hepatic artery contributing around 20%. This unique dual blood supply is essential for the liver's function in detoxification, metabolism, and storage of nutrients. The hepatic artery branches into smaller arteries, such as the right and left hepatic arteries, which supply the liver lobules. In contrast, the portal vein branches into smaller veins, including the right and left portal veins, which also supply the liver lobules.

**Why Each Wrong Option is Incorrect**
**Option A:** This option incorrectly states that the hepatic artery supplies 80% of the liver's blood supply, which is not true. The hepatic artery's contribution is significantly lower than the portal vein's.
**Option C:** This option is incorrect because it states that the hepatic artery and portal vein contribute equally to the liver's blood supply, which is not the case. The portal vein is the primary source of blood for the liver.
**Option D:** This option is incorrect because it states that the liver receives 100% of its blood supply from the hepatic artery, which is not true. The liver receives blood from both the hepatic artery and the portal vein.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the liver's dual blood supply allows it to function in both oxygenated and deoxygenated environments, which is crucial for its detoxification and metabolic functions.

**✓ Correct Answer: B. 20% hepatic artery, 80% portal vein**