**Core Concept**
The patient has chronic hepatitis C virus (HCV) infection, characterized by the presence of antibodies against HCV and normal liver enzymes (AST and ALT). This scenario highlights the need for further evaluation to assess the liver damage and determine the best course of management.

**Why the Correct Answer is Right**
In asymptomatic patients with chronic HCV infection and normal liver enzymes, a liver biopsy is recommended to assess the extent of liver fibrosis and inflammation. This is crucial in determining the need for antiviral therapy, which can prevent progression to cirrhosis and liver cancer. Liver biopsy is essential in this scenario because it provides a direct assessment of liver damage, which cannot be accurately predicted by liver enzymes or imaging studies alone.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a liver biopsy is not necessary in all cases of chronic HCV infection. However, in asymptomatic patients with normal liver enzymes, a biopsy is recommended to assess the extent of liver damage.

**Option B:** This option is incorrect because a liver biopsy is not a diagnostic test for HCV infection. Antibodies against HCV are used for diagnosis, and a biopsy is used to assess the extent of liver damage in patients with established HCV infection.

**Option C:** This option is incorrect because antiviral therapy is not always necessary in patients with chronic HCV infection and normal liver enzymes. A liver biopsy is recommended to assess the extent of liver damage before initiating antiviral therapy.

**Option D:** This option is incorrect because liver ultrasound is not a substitute for liver biopsy in assessing the extent of liver damage in patients with chronic HCV infection and normal liver enzymes.

**Clinical Pearl / High-Yield Fact**
In patients with chronic HCV infection, a liver biopsy is recommended to assess the extent of liver fibrosis and inflammation, as this information is crucial in determining the need for antiviral therapy.

**Correct Answer:** C.