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
Double bubble sign seen in : 
Select and explain. 
A. Duodenal atresia, B. Duodenal stenosis, C. Volvulus, D. All
D: All
Answer: D: All 
Explanation: Ans. is 'a', 'b' & 'c' i.e. Duodenal atresia, Duodenal stenosis and Volvulus