This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Henoch-Schonlein purpura is characterized by the deposition of the following immunoglobulin around the vessels - 
Select and explain. 
A. IgM, B. IgG, C. IgA, D. IgE
C: IgA
Answer: C: IgA 
Explanation: Henoch-Schonlein purpura

Henoch-Schonlein purpura is vasculitis of small vessels (capillaries, venule or arterioles) and characterized by deposition of IgA in the wall of involved vessels.
H.S. purpura is characterized by a tetrad of purpura, arthritis, glomerulonephritis, and abdominal pain.
All changes resulting from the deposition of circulating immune complexes, containing IgA and complement on the endothelium of the blood vessels throughout the body and within the glomerular mesangial regions.
It is most common in children under the age of 10 years but HSP can also affect older children and adults.