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
ANCA is positive in - 
Select and explain. 
A. Wegener's granulomatosis, B. Churg strauss syndrome, C. Microscopic PAN, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None