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 positivity indicates, antibody formed against- \nSelect and explain. \nA. Proteinase 3, B. Myeloperoxidase, C. Cytoplasmic antinuclear antibody, D. Anti centromere antibody', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]