**Core Concept:** The hepatic artery is one of the primary blood vessels supplying the liver with oxygenated blood. It is responsible for delivering approximately 20% of the total blood flow to the liver. The liver receives blood from two major sources: the portal vein (which carries deoxygenated blood from the intestines) and the hepatic artery (which carries oxygenated blood from the aorta).

**Why the Correct Answer is Right:** The correct answer, 20%, is based on the understanding that the liver receives approximately 70% of its blood flow via the portal vein and 30% via the hepatic artery. The hepatic artery is responsible for supplying oxygenated blood to the liver, which is essential for its functioning as a crucial organ in various physiological processes.

**Why Each Wrong Option is Incorrect:**
A. 50%: This is an incorrect answer because it does not accurately reflect the proportionate contribution of the hepatic artery to the liver's blood flow. The hepatic artery is responsible for only 20% of the blood flow to the liver.

B. 30%: This answer is also incorrect as the hepatic artery contributes only 30% of the liver's blood flow, which is less than the correct answer (20%).

C. 60%: Similar to option A and B, this answer is incorrect as the hepatic artery provides 20% of the liver's blood flow.

D. 80%: This option is wrong because the portal vein supplies 70% of the liver's blood flow, not 80%, and the hepatic artery contributes only 20%.

**Clinical Pearl:** A deep understanding of the liver's blood supply is crucial for medical professionals, as it helps in understanding the liver's role in detoxification, bile production, and other vital physiological processes. This knowledge also helps in interpreting liver function test results and diagnosing conditions such as liver cirrhosis, where a reduced blood flow to the liver can lead to impaired liver function.