**Core Concept**
The patient's presentation of generalized edema, skin ulceration, hypertension, subnephrotic proteinuria, microscopic hematuria, decreased serum complement levels, and positive anti-hepatitis C antibodies suggests an immune-mediated glomerulonephritis associated with hepatitis C infection.

**Why the Correct Answer is Right**
The patient's symptoms and lab findings are consistent with membranoproliferative glomerulonephritis (MPGN), a type of glomerulonephritis characterized by the deposition of immune complexes in the glomeruli, leading to inflammation and damage. The decreased serum complement levels and presence of anti-hepatitis C antibodies suggest that the hepatitis C virus is playing a role in the pathogenesis of the disease. The subnephrotic proteinuria and microscopic hematuria are indicative of glomerular damage.

**Why Each Wrong Option is Incorrect**
**Option A:** Focal segmental glomerulosclerosis (FSGS) typically presents with nephrotic range proteinuria (>3.5g/day) and is not associated with decreased serum complement levels or anti-hepatitis C antibodies.

**Option B:** IgA nephropathy typically presents with acute or episodic hematuria and is not associated with decreased serum complement levels or anti-hepatitis C antibodies.

**Option C:** Lupus nephritis can present with a wide range of renal manifestations, but the presence of anti-hepatitis C antibodies is not a typical association.

**Clinical Pearl / High-Yield Fact**
Membranoproliferative glomerulonephritis is a type of glomerulonephritis that can be associated with various underlying conditions, including infections, autoimmune disorders, and lymphoproliferative disorders.

**Correct Answer:** C. Membranoproliferative glomerulonephritis