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': 'Which of the following is the best marker for drug induced lupus? \nSelect and explain. \nA. Anti histone antibodies, B. Anti DS DNA, C. ANA, D. Anti Smith Ab', 'role': 'user'}, {'content': "Answer: A \nExplanation: Drug induced lupus is associated with anti histone antibodies which are positive in 95% of cases. Ref: Harrison's Principles of Internal Medicine, 17th Edition, Page 2076; 16th/ 1961, 1967; Pathologic Basis of Disease, Robbins, 7th Edition, Page 229 & 235; Drug-Induced Diseases: Prevention, Detection, and Management, James E. Tisdale, 2nd Edition, Section 2, Page 108", 'role': 'assistant'}]