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: Pharmacology
[{'content': 'Aldosterone action is on : \nSelect and explain. \nA. Proximal tubule, B. Distal tubules, C. Loop of Henle, D. Collecting duct', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]