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': 'Pyoderma-gangrenosum is most commonly associated with - \nSelect and explain. \nA. Ulcerative colitis, B. Crohns disease, C. Amoebic colitis, D. Ischemic colitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]