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: Surgery
[{'content': 'Ankylosing apondylitis is associated with ? \nSelect and explain. \nA. HLA-B27, B. HLA-B-8, C. HLA - DW4/DR4, D. HLA - DR3', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., HLA-B27 There is strong correlation with HLA-B27 90-95% of cases are positive for HLA - B27.", 'role': 'assistant'}]