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': 'The part of nephron "least permeable to water" is \nSelect and explain. \nA. Proximal tubule, B. Descending Limb of loop of Henle, C. Ascending limb of loop of Henle, D. Collecting tubule', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]