Number of segments in liver is:

**Core Concept**
The liver is divided into distinct anatomical regions, known as segments or lobes, which play a crucial role in liver function and surgical planning. The liver's segmental anatomy is based on the Couinaud classification, which divides the liver into eight distinct segments.

**Why the Correct Answer is Right**
The correct answer is based on the Couinaud classification system, which was developed by French surgeon Paul Couinaud in the 1950s. This system divides the liver into eight segments (I to VIII) based on the distribution of the hepatic veins and portal veins. Each segment has a unique vascular supply and drainage, which is essential for liver function and surgical planning. The Couinaud classification is widely used in clinical practice and is a fundamental concept in hepatobiliary surgery.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the liver is not divided into four segments. While the liver has a lobar anatomy, the Couinaud classification system divides it into eight distinct segments.

**Option B:** This option is incorrect because the liver is not divided into five segments. The Couinaud classification system is the most widely used and accepted system for dividing the liver into segments.

**Option C:** This option is incorrect because the liver is not divided into three segments. While the liver has a lobar anatomy, the Couinaud classification system divides it into eight distinct segments.

**Clinical Pearl / High-Yield Fact**
The Couinaud classification system is essential for liver surgeons and radiologists to accurately diagnose and treat liver diseases, such as liver cancer and cirrhosis. Understanding the segmental anatomy of the liver is critical for successful liver resection and transplantation surgery.

**Correct Answer:** C. 8.