This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal system, Subject name: Anatomy
[{'content': 'Antibody found in myositis \nSelect and explain. \nA. Anti jo 1, B. Anti scl 70, C. Anti Sm, D. Anti ku', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer Harrison 17th/2038', 'role': 'assistant'}]