This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2018, Subject name: Medicine
[{'content': 'A patient presents with cutaneous vasculitis, glomerulonephritis and peripheral neuropathy. What investigation is to be performed next for work up? \nSelect and explain. \nA. ANCA, B. RA factor, C. HBsAg, D. CRP', 'role': 'user'}, {'content': 'Answer: A \nExplanation: C-ANCA (Ag against which C ANCA is directed against is -Proteinase 3) P-ANCA - (Ag against which P ANCA is directed against is -MPO)', 'role': 'assistant'}]