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: Medicine
[{'content': 'Feature of Henoch-Scholein purpura includes -a) Occur only in elderly personb) Palpable purpurac) Thrombocytopeniad) Arthralgia \nSelect and explain. \nA. bd, B. d, C. ab, D. ac', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]