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': "C-ANCA associated with - \nSelect and explain. \nA. Wegener's granulomatosis, B. Microscopic polyangitis, C. Churg straws syndrome, D. PAN", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]