This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
Double bubble sign in seen in - 
Select and explain. 
A. Duodenal atresia, B. Jejunal atresia, C. Pyloric stenosis, D. Hirschprung disease
A: Duodenal atresia
Answer: A: Duodenal atresia 
Explanation: The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally Pathology Causes include congenital obstruction duodenal web duodenal atresia duodenal stenosis annular pancreas midgut volvulus external compression of the dudenum choledochal cyst mesenteric duplication cyst intramural duodenal haematoma preduodenal portal vein retroperitoneal tumour superior mesenteric artery syndrome