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: Pediatrics
[{'content': "Vomiting on the first day of baby's life may be caused by all of the following except- \nSelect and explain. \nA. Pyloric stenosis, B. Oesophageal atresia, C. Aerophagy, D. Amniotic gastritis", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Pyloric stenosis", 'role': 'assistant'}]