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': 'Which does not contribute to Enterobillary Fistula ? \nSelect and explain. \nA. Duodenal ulcer, B. Gall stones, C. Gastric ulcer, D. Carcinoma gall bladder', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e. Gastric ulcer", 'role': 'assistant'}]