This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'Which pa of the nephron is impermeable to water? \nSelect and explain. \nA. A, B. B, C. C, D. D', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The thick ascending limb of loop of henle is completely impermeable to water, hence it is also called as the diluting segment of the nephron Ref: Guyton review 3rd edition/page 83', 'role': 'assistant'}]