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: Surgery
[{'content': 'Condition which does not cause metabolic acidosis \nSelect and explain. \nA. Renal failure, B. Pyloric stenosis, C. Biliary fistula, D. Ureterosigmoidostomy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pyloric stenosis causes Metabolic alkalosis. Rest all causes metabolic acidosis.', 'role': 'assistant'}]