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
All of the following operations for morbid obesity are restrictive, Except: 
Select and explain. 
A. Veical banded gastroplasty, B. Adjustable gastric banding, C. Roux-en-Y gastric bypass, D. Douodenal switch
D: Douodenal switch
Answer: D: Douodenal switch 
Explanation: Ans is 'd' i.e Duodenal switch