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
[{'content': "A robust male baby with vigorous feeding and immediate vomiting at 2 months of age. Most probable diagnosis is \nSelect and explain. \nA. Paralytic ileus, B. Hirschsprung's disease, C. Brain tumor, D. Congenital hyperophic pyloric stenosis", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Congenital hyperophic pyloric stenosis is seen between 3 rd and 6 the week of age of an infant because the time taken by the hyperophied muscle to cause complete obstruction is between 3rd and 6 the week, as well as the congenital hyperophic pyloric stenosis is most commonly seen in firstborn males. Reference: SRB 5 the edition page no. 821', 'role': 'assistant'}]