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': 'The preferred bypass procedure in case of non resectable carcinoma of head of pancreas is? \nSelect and explain. \nA. Cholecystojejunostomy, B. Cholecystogastrostomy, C. Choledochoduodenostomy, D. Choledochojejunostomy', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Cholecystojejunostomy", 'role': 'assistant'}]