**Core Concept**
Henoch-Schönlein purpura (HSP) is a form of vasculitis that affects small blood vessels, characterized by **immune complex deposition** and **inflammation**. It is often seen in children and young adults. The condition is also known as IgA vasculitis due to the involvement of **IgA antibodies**.

**Why the Correct Answer is Right**
The typical age range for HSP presentation is between 3 to 15 years, with a peak incidence around 4-6 years. This condition is more common in children than in adults, which is why the correct answer relates to this pediatric age group. The exact mechanism involves the deposition of **IgA immune complexes** in the small vessels, leading to **inflammation** and the characteristic purpuric rash.

**Why Each Wrong Option is Incorrect**
**Option A:** This age range might be too young or too old for the typical presentation of HSP.
**Option B:** This could be a possible age range but is not as specific as the correct answer.
**Option D:** This age range is more commonly associated with other conditions and is not typical for HSP.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that HSP often presents with a tetrad of symptoms: **purpura**, **arthritis**, **abdominal pain**, and **renal involvement**. Recognizing these symptoms, especially in children, is crucial for early diagnosis.

**Correct Answer:** C. 3-15 years