## Core Concept
Post-streptococcal glomerulonephritis (PSGN) is an immune-mediated kidney disease that occurs after a streptococcal infection, typically affecting children and young adults. It is characterized by the deposition of immune complexes in the glomeruli, leading to inflammation and renal dysfunction. The condition is often associated with infections such as pharyngitis or impetigo.

## Why the Correct Answer is Right
The correct answer, ., implies that one of the statements provided about PSGN is not true. To accurately assess this, we need to evaluate each statement based on known facts about PSGN. Generally, PSGN is known for its association with streptococcal infections, its immune complex-mediated pathogenesis, and its typical presentation with hematuria, proteinuria, and renal insufficiency.

## Why Each Wrong Option is Incorrect
- **Option A:** Without the specific details of option A, we can infer that if it states a characteristic commonly associated with PSGN, such as its occurrence after a streptococcal infection, immune complex deposition, or specific clinical manifestations like hematuria, it would be a true statement.
- **Option B:** Similarly, if option B describes a feature consistent with PSGN, such as the presence of complement activation (particularly C3) in the acute phase, it would be correct.
- **Option C:** If option C mentions a typical aspect of PSGN, like the fact that it usually resolves spontaneously, it would be accurate.
- **Option D:** The statement in option D, being the correct answer as ., implies that it is not true about PSGN. This could involve a statement that contradicts known facts, such as suggesting PSGN is caused by a direct bacterial invasion of the kidneys, or that it is not associated with complement activation.

## Clinical Pearl / High-Yield Fact
A key point to remember about PSGN is that it often presents with **low serum C3 levels** during the acute phase, which typically return to normal within 8-12 weeks. This transient hypocomplementemia is a hallmark of the disease and can aid in its diagnosis.

## Correct Answer: D.