**Core Concept**
Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that can affect multiple organ systems, including the kidneys. Renal involvement in SLE is a common and potentially life-threatening complication. The renal lesions in SLE are primarily due to the deposition of immune complexes and complement components in the glomeruli.

**Why the Correct Answer is Right**
The correct answer is **Diffuse proliferative glomerulonephritis (DGN)**. DGN is characterized by the presence of diffuse glomerular inflammation and proliferation, which can lead to significant loss of renal function. The pathogenesis of DGN involves the deposition of immune complexes and complement components, such as C3 and C4, in the glomeruli. This leads to the activation of the complement system and the recruitment of inflammatory cells, resulting in glomerular damage and scarring.

**Why Each Wrong Option is Incorrect**
**Option A:** Focal proliferative glomerulonephritis is a less common form of renal involvement in SLE and typically presents with fewer and less severe glomerular lesions.
**Option B:** Membranous nephropathy is a type of glomerulonephritis that can be associated with SLE, but it is not the most common form of renal involvement.
**Option C:** Minimal change disease is a type of glomerulopathy that is typically seen in children and is not a common form of renal involvement in SLE.

**Clinical Pearl / High-Yield Fact**
The presence of hematuria and proteinuria in a patient with SLE should raise suspicion for renal involvement, and a renal biopsy should be considered to confirm the diagnosis.

**Correct Answer:** C. Membranous nephropathy is a type of glomerulonephritis that can be associated with SLE, but it is not the most common form of renal involvement.