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': 'Most common extraintestinal complication of ulcerative colitis is \nSelect and explain. \nA. Arthritis, B. Uveitis, C. Episcleritis, D. Pyoderma gangrenosum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: M/c Arthritis\nPeripheral arthritis - responds to treatment\nAxial arthritis -does not responds to treatment.', 'role': 'assistant'}]