**Core Concept**
Lamivudine is an antiviral medication used to treat chronic hepatitis B infection. The decision to initiate lamivudine therapy is based on the presence of liver inflammation and damage, which can be assessed through liver function tests, particularly alanine transaminase (ALT) levels.

**Why the Correct Answer is Right**
Lamivudine is recommended for patients with chronic hepatitis B who have elevated liver enzymes, specifically ALT levels greater than 2 times the upper limit of normal (ULN). This indicates active liver inflammation and damage, which can lead to cirrhosis and liver failure if left untreated. Elevated ALT levels are a marker of liver injury and are used to monitor the effectiveness of antiviral therapy.

**Why Each Wrong Option is Incorrect**
**Option A:** HBeAg positive status alone does not dictate the need for lamivudine therapy. HBeAg positivity indicates viral replication, but ALT levels should also be considered to assess liver inflammation.
**Option B:** HBeAg negative status does not necessarily indicate a need for lamivudine. Some patients with HBeAg negative chronic hepatitis B may have minimal liver inflammation and can be managed with surveillance alone.
**Option D:** Viral DNA levels > 10^6 copies/mL may indicate active viral replication, but ALT levels are a more critical factor in determining the need for antiviral therapy.

**Clinical Pearl / High-Yield Fact**
Monitor ALT levels regularly in patients on lamivudine therapy to assess treatment response and detect potential resistance. A sustained reduction in ALT levels is a good indicator of effective treatment.

**✓ Correct Answer: C. ALT > 2 ULN**