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: Orthopaedics
[{'content': 'All are true regarding Anklosing spondylitis except - \nSelect and explain. \nA. Sacroilitis, B. HLA -B27, C. Iridocyclitis, D. More common in females', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ankylosing spondylitis is more common in males (not females).', 'role': 'assistant'}]