**Core Concept**
SLE (Systemic Lupus Erythematosus) is an autoimmune disease that can affect various organs, including the kidneys, leading to lupus nephritis. The renal pathology in SLE is characterized by inflammation and damage to the glomeruli, which are responsible for filtering waste and excess fluids from the blood.

**Why the Correct Answer is Right**
Lupus nephritis in SLE is primarily caused by the deposition of immune complexes, which are formed when antibodies bind to antigens. These immune complexes accumulate in the glomeruli, triggering an inflammatory response that damages the glomerular basement membrane and the surrounding tissue. The resulting renal pathology can lead to impaired kidney function, including proteinuria, hematuria, and decreased glomerular filtration rate.

**Why Each Wrong Option is Incorrect**
**Option A:** Focal segmental glomerulosclerosis (FSGS) is a type of glomerular disease that can be caused by various factors, including genetic mutations and viral infections. However, it is not typically associated with SLE.
**Option B:** Membranous nephropathy is a type of glomerulonephritis characterized by thickening of the glomerular basement membrane. While it can be caused by autoimmune diseases, it is not a primary feature of SLE.
**Option C:** Minimal change disease is a type of glomerulonephritis characterized by normal-appearing glomeruli on light microscopy. It is often associated with nephrotic syndrome and can be caused by various factors, including infections and allergies. However, it is not typically associated with SLE.

**Clinical Pearl / High-Yield Fact**
Lupus nephritis is a major complication of SLE and can be prevented or delayed with appropriate immunosuppressive therapy. Early detection and treatment of renal involvement are critical to preventing long-term kidney damage and improving patient outcomes.

**Correct Answer: A. Focal segmental glomerulosclerosis (FSGS) is not a primary feature of SLE.**