**Core Concept**
The question is testing the association between nephrotic syndrome and bronchiectasis. The underlying principle is that certain diseases can have extrarenal manifestations, which is a classic concept in internal medicine.

**Why the Correct Answer is Right**
Nephrotic syndrome is characterized by massive proteinuria, hypoalbuminemia, and edema. In patients with bronchiectasis, the most probable diagnosis is membranous nephropathy (MN). Membranous nephropathy is an immune-complex-mediated disease that can be secondary to chronic infections, including those affecting the respiratory system like bronchiectasis. The immune complexes deposit in the glomerular basement membrane, leading to its thickening and proteinuria.

**Why Each Wrong Option is Incorrect**
**Option A:** While minimal change disease is a common cause of nephrotic syndrome in children, it is less likely in adults, especially those with a history of chronic infections like bronchiectasis.

**Option B:** Focal segmental glomerulosclerosis (FSGS) is another common cause of nephrotic syndrome, but it is not typically associated with bronchiectasis.

**Option C:** Membranoproliferative glomerulonephritis is a disease that can present with nephrotic syndrome, but it is not the most probable diagnosis in this scenario.

**Clinical Pearl / High-Yield Fact**
In patients with chronic infections, including bronchiectasis, membranous nephropathy should be considered as a potential cause of nephrotic syndrome. This is a classic example of an extrarenal manifestation of a systemic disease.

**Correct Answer:** C. Membranous nephropathy.