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': "CANCA Positivity is specific for: \nSelect and explain. \nA. Polyaeritis Nodosa, B. Wegener's granulomatosis, C. Henoch shontein purpura, D. Churg strouss syndrome", 'role': 'user'}, {'content': "Answer: B \nExplanation: Answer is B (Wegener's granulomatosis): CANCA refers to Cytoplasmic Antineutrophilic cytoplasmic antibodies and its presence is highly specific for Wegener's granulomatosis", 'role': 'assistant'}]