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': 'Proximal & distal renal tubular acidosis is differentiated by all, except: \nSelect and explain. \nA. Stones in kidney, B. Hypokalemia, C. Daily acid secretion, D. Presence of Fanconi syndrome', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (Hypokalemia):', 'role': 'assistant'}]