This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
What is the most common cause of gastric outlet obstruction in a 4-week-old baby 
Select and explain. 
A. Annular pancreas, B. Foreign body, C. Congenital hyperophic pyloric stenosis, D. Duodenel atresia
C: Congenital hyperophic pyloric stenosis
Answer: C: Congenital hyperophic pyloric stenosis 
Explanation: It is seen between 3rd and 6 the week of age of an infant because it&;s the time taken by the hyperophied muscle to cause complete obstruction. SRB edition 5th page no: 821