Final answer:
The correct answer is A) Henoch-Schönlein purpura, a form of vasculitis causing palpable purpura, arthralgia, and abdominal pain.
Step-by-step explanation:
Palpable purpura that begins on the buttocks and lower legs, combined with arthralgia (joint pain) and abdominal pain, are symptoms associated with Henoch-Schönlein purpura (HSP). HSP is a form of vasculitis, which refers to the inflammation of the blood vessels that can cause blood to leak from damaged vessels, forming visible purple spots known as purpura. This condition can also lead to acute glomerulonephritis, affecting the kidneys. Based on these clinical features and the options provided, the correct answer is A) Henoch-Schönlein purpura.