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: Physiology
[{'content': 'Least clearance is for among these \nSelect and explain. \nA. Glucose, B. Inulin, C. Urea, D. Creatinine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Glucose is completely reabsorbed in proximal tubules. So its clearance is zero.', 'role': 'assistant'}]