This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': "Which of the following is NOT associated with ankylosing spondylitis: \nSelect and explain. \nA. SLE, B. Reiter's syndrome, C. Psoriatic ahropathy, D. Crohn's disease", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ankylosing spondylitis is an inflammatory disorder of unknown cause Primarily affects the axial skeleton; peripheral joints and extraaicular structuresOlder names: Marie-Strumpell disease or Bechterew's diseaseTypically associated with HLA-B27(ref:Harrison's 18/e p2774, 2775)", 'role': 'assistant'}]