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: Medicine
[{'content': 'All are features of renal tubular acidosis type I except - \nSelect and explain. \nA. Stone in kidney, B. No anion gap, C. Hypokalemia, D. Fanconi syndrome', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]