**Core Concept**
Diabetic nephropathy is a microvascular complication of diabetes mellitus, characterized by damage to the glomeruli and tubules of the kidneys. Reversible diabetic nephropathy refers to the early stages of diabetic nephropathy where kidney function can be restored with timely intervention.

**Why the Correct Answer is Right**
Reversible diabetic nephropathy is characterized by hyperfiltration, which leads to glomerular hypertrophy and increased glomerular filtration rate (GFR). This is due to the increased glucose levels in the blood, which activate the hexosamine pathway, leading to increased synthesis of TGF-β (Transforming Growth Factor-beta), a potent fibrogenic cytokine. The increased TGF-β stimulates the mesangial cells to proliferate and produce extracellular matrix, leading to glomerular hypertrophy and hyperfiltration.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a characteristic of irreversible diabetic nephropathy, where the kidneys are irreversibly damaged and kidney function cannot be restored.

**Option B:** This option is incorrect because it is a characteristic of diabetic nephropathy, but not specifically reversible diabetic nephropathy.

**Option C:** This option is incorrect because it is a treatment for diabetic nephropathy, not a characteristic of reversible diabetic nephropathy.

**Clinical Pearl / High-Yield Fact**
The early stages of diabetic nephropathy are characterized by hyperfiltration, which can be reversed with timely intervention, including tight blood glucose control and ACE inhibitors.

**Correct Answer:** B. Hyperfiltration, glomerular hypertrophy, and increased GFR.