This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
[{'content': 'Olive shaped mass on feeding is pathognomonic of: \nSelect and explain. \nA. Hypertrophic pyloric stenosis, B. Duodenal atresia, C. Jejuna atresia, D. Ileal stenosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Hypertrophic pyloric stenosisRef: Sabiston 20th Edition, Page 1869* If olive shaped mass is palpable then no other investigation is needed to confirm the diagnosis (Even USG is not needed)', 'role': 'assistant'}]