**Core Concept**
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, often arising in the setting of chronic liver disease and cirrhosis. The pathogenesis of HCC involves genetic and epigenetic alterations, including mutations in tumor suppressor genes and oncogenes.

**Why the Correct Answer is Right**
HCC is characterized by the presence of various clinical and histopathological features, including:
- **Alpha-fetoprotein (AFP) elevation**: AFP is a tumor marker commonly elevated in HCC, although it can also be elevated in other conditions such as cirrhosis and pregnancy.
- **Portal vein thrombosis**: Portal vein thrombosis is a complication of HCC, often seen in advanced disease, and can lead to liver failure and portal hypertension.
- **Hepatocyte growth factor (HGF) expression**: HGF is a growth factor involved in the regulation of cell growth and motility, and its expression is often seen in HCC.

**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect as **cirrhosis** is a common underlying condition for HCC, often resulting from chronic hepatitis B or C infection, alcohol abuse, or non-alcoholic steatohepatitis (NASH).
**Option B:** is incorrect as **AFP elevation** is a common feature of HCC, although it can also be elevated in other conditions.
**Option C:** is incorrect as **portal vein thrombosis** is a complication of HCC, often seen in advanced disease.

**Clinical Pearl / High-Yield Fact**
HCC often arises in the setting of chronic liver disease and cirrhosis, and the risk of HCC is increased in patients with cirrhosis, particularly those with hepatitis B or C infection.

**Correct Answer:** D