- The correct answer is Hepatitis B virus because it is a well-established biological carcinogen that causes chronic liver infection leading to hepatocellular carcinoma.
- This virus integrates into host DNA, promoting genetic mutations and oncogenesis.
- While Epstein-Barr virus and Human papillomavirus are also carcinogenic, Hepatitis B virus is uniquely linked to liver cancer.
- Helicobacter pylori is a bacterial carcinogen, not viral.

Reference: Robbins Basic Pathology, 10th Edition, Chapter 9, p. 282