This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Benign Gastric Disease, Subject name: Surgery
[{'content': 'Most common biochemical abnormality in congenital pyloric stenosis. \nSelect and explain. \nA. Hyperkalemic metabolic acidosis, B. Hypokalemic metabolic acidosis, C. Hyperkalemic metabolic alkalosis, D. Hypokalemic metabolic alkalosis', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e. Hypokalemic metabolic alkalosis Repeated vomiting leads to hypochloremic, hypokalemic metabolic alkalosis. The urine is alkaline initially but eventually it becomes acidic (paradoxical aciduria)", 'role': 'assistant'}]