This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, 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. Cholecystogatrostomy, C. Choledochoduodenostomy, D. Choledochojejunostomy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: It is preferable to use bile duct rather than the gall bladder.Cholecystojejunostomy is easier to perform,but the bile must then drain through the cystic duct,which is narrow and ,if the cystic duct is inseed low into the bile duct,it is vulnerable to occlusion by tumour growth. Bailey & Love 26th edition ,page no.1140 .', 'role': 'assistant'}]