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': 'Best marker for drug induced lupus is - \nSelect and explain. \nA. Anti histone antibodies, B. Anti ds DNA, C. ANA, D. Anti smith Ab', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]