**Core Concept**
Bence Jones proteinuria refers to the presence of free light chains of immunoglobulins, specifically kappa (κ) or lambda (λ), in the urine. This phenomenon is a hallmark of certain types of plasma cell dyscrasias, including multiple myeloma and Waldenström macroglobulinemia.

**Why the Correct Answer is Right**
Bence Jones proteins are produced by neoplastic plasma cells and are typically composed of either kappa or lambda light chains. In multiple myeloma, the malignant plasma cells produce excess amounts of light chains, which are then excreted in the urine. The presence of Bence Jones proteins in the urine is a diagnostic clue for multiple myeloma, and their identification is often confirmed using immunofixation electrophoresis or mass spectrometry.

**Why Each Wrong Option is Incorrect**
**Option A:** Multiple sclerosis is an autoimmune disease affecting the central nervous system, and Bence Jones proteinuria is not typically associated with this condition.
**Option B:** Chronic kidney disease may cause proteinuria, but the presence of Bence Jones proteins is not a characteristic feature of this condition.
**Option C:** Systemic lupus erythematosus is a systemic autoimmune disease that can cause various renal manifestations, but Bence Jones proteinuria is not a typical finding in this condition.

**Clinical Pearl / High-Yield Fact**
The presence of Bence Jones proteins in the urine is a critical diagnostic clue for multiple myeloma, and their detection should prompt further evaluation, including bone marrow biopsy and serum protein electrophoresis.

**Correct Answer: D. Multiple myeloma**