**Core Concept**
Hypersensitivity angiitis, also known as hypersensitivity vasculitis, is a form of inflammation of blood vessels that is caused by an immune response to certain medications, infections, or other stimuli. This condition is characterized by the deposition of immune complexes and the activation of complement, leading to the release of various pro-inflammatory mediators.

**Why the Correct Answer is Right**
The correct answer is related to the underlying pathophysiology of hypersensitivity angiitis, which involves the activation of the immune system and the release of pro-inflammatory mediators. This leads to the inflammation of blood vessels, which can manifest as palpable purpura, urticaria, or other skin lesions. The condition is often associated with the deposition of immune complexes, which are formed when antibodies bind to antigens.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because hypersensitivity angiitis is not primarily associated with autoimmune disorders.
**Option B:** This option is incorrect because hypersensitivity angiitis is not a form of vasculitis that is typically associated with granulomatous inflammation.
**Option C:** This option is incorrect because hypersensitivity angiitis is not a type of vasculitis that is primarily associated with the deposition of amyloid.

**Clinical Pearl / High-Yield Fact**
Hypersensitivity angiitis is often associated with the use of certain medications, such as penicillin and sulfonamides, and can also be triggered by infections, such as streptococcal pharyngitis.

**Correct Answer: D. Henoch-Schönlein purpura**