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
A newborn presenting with intestinal obstruction and constipation showed, on abdominal X ray, multiple air fluid levels. The diagnosis is not likely to be: 
Select and explain. 
A. Pyloric obstruction, B. Duodenal atresia, C. Ileal atresia, D. Ladd's bands
A: Pyloric obstruction
Answer: A: Pyloric obstruction 
Explanation: In Pyloric obstruction there will be only single air fluid level. For multiple air fluid levels on X ray obstruction should be distal to duodenal bulb. Ref: Walker's Pediatric Gastrointestinal Disease: Physiology, Diagnosis and Management By Ronald E. Kleinman, 2008, Page 122