This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
[{'content': 'Drugs increasing renin levels except: \nSelect and explain. \nA. Clonidine, B. Hydralazine, C. Nifedipine, D. Captopril', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. ClonidineRenin levels are increased when there is reflex sympathetic outflow. Vasodilators and ACE inhibitors results in reflex increase in renin activity. Clonidine on the other hand decrease the sympathetic outflow.', 'role': 'assistant'}]