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: Radiology
Double bubble sign in an X-ray abdomen is indicative of: 
Select and explain. 
A. Annular pancreas, B. Ileal atresia, C. Anal rectal malformation, D. All of the above
A: Annular pancreas
Answer: A: Annular pancreas 
Explanation: Ans. Annular pancreas