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': 'Internal fistula is most common between gall bladder and: \nSelect and explain. \nA. Colon, B. Duodenum Ist pa, C. Jejunum, D. Transverse colon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (Duodenum 1st pa)', 'role': 'assistant'}]