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': 'All of the following operations for morbid obesity are restrictive, Except: \nSelect and explain. \nA. Veical banded gastroplasty, B. Adjustable gastric banding, C. Roux-en-Y gastric bypass, D. Douodenal switch', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans is 'd' i.e Duodenal switch", 'role': 'assistant'}]