**Core Concept**
Nephritic syndrome is characterized by inflammation of the glomeruli, leading to hematuria, proteinuria, and hypertension. This condition is often associated with crescent formation, a hallmark of severe glomerular damage.

**Why the Correct Answer is Right**
The correct answer is post-streptococcal glomerulonephritis (PSGN), a classic example of nephritic syndrome. PSGN occurs after a streptococcal infection, particularly streptococcal pharyngitis or skin infections. The immune response to the streptococcal antigens triggers an autoimmune reaction, leading to the deposition of immune complexes in the glomeruli. This results in inflammation, crescent formation, and subsequent renal dysfunction. The characteristic features of PSGN include hematuria, proteinuria, hypertension, and renal failure.

**Why Each Wrong Option is Incorrect**
**Option A:** Acute tubular necrosis (ATN) typically presents with oliguria, anuria, and acute kidney injury, but it is not characterized by nephritic syndrome.

**Option B:** Minimal change disease (MCD) is a cause of nephrotic syndrome, characterized by massive proteinuria, hypoalbuminemia, and edema, but it does not present with the features of nephritic syndrome.

**Option C:** Chronic kidney disease (CKD) is a condition of gradual renal deterioration, often leading to end-stage renal disease, but it does not typically present with the acute inflammatory features of nephritic syndrome.

**Clinical Pearl / High-Yield Fact**
PSGN often presents with a characteristic "flank pain" and "hematuria" after an upper respiratory tract infection, and it can be confirmed by the presence of anti-streptolysin O (ASO) titer or antistreptococcal DNAse B (anti-DNAse B) antibodies.

**Correct Answer:** A. Post-streptococcal glomerulonephritis.