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
Which of the following drug decreases plasma renin activity 
Select and explain. 
A. Enalapril, B. Nefidipine, C. Hydralazine, D. Clonidine
D: Clonidine
Answer: D: Clonidine 
Explanation: Clonidine REF: Goodman Gillman page 525, KDT 6th edition page 547-548 Repeat from December 2008 Plasma renin activity is increased by reflex increase in sympathetic discharge. Clonidine decreases central sympathetic outflow and thus will decrease plasma renin activity. Vasodilators and ACE inhibitors result in reflex increase in plasma renin activity.