**Core Concept**
HBV (Hepatitis B Virus) is a major cause of chronic liver disease and hepatocellular carcinoma. HBV has several components, including the envelope proteins (HBsAg, HBeAg, and HBcAg), the core protein, and the precore region. Glomerulonephritis is a form of kidney inflammation that can be triggered by immune complexes formed against HBV antigens.

**Why the Correct Answer is Right**
The correct answer is the component of HBV that is primarily responsible for triggering immune complex-mediated glomerulonephritis. The core protein of HBV is the main antigen responsible for the formation of immune complexes that deposit in the glomeruli, leading to inflammation and damage. This is due to the fact that the core protein is highly immunogenic and can stimulate a strong immune response, leading to the production of antibodies against it. These antibodies can then bind to the core protein, forming immune complexes that are deposited in the glomeruli, causing inflammation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the envelope proteins (HBsAg, HBeAg, and HBcAg) are primarily involved in the viral replication and transmission, but not directly in the formation of immune complexes that cause glomerulonephritis.

**Option B:** This option is incorrect because the precore region is involved in the regulation of HBV replication and the production of HBeAg, but not directly in the formation of immune complexes that cause glomerulonephritis.

**Option D:** This option is incorrect because it is not a valid component of HBV.

**Clinical Pearl / High-Yield Fact**
HBV-related glomerulonephritis is a form of immune complex-mediated glomerulonephritis that is triggered by the deposition of immune complexes containing HBV antigens in the glomeruli. This condition is more common in individuals with chronic HBV infection and can be a serious complication of the disease.

**Correct Answer:** C.