This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
All of the following antihypeensive drugs increase plasma rein activity except : 
Select and explain. 
A. Clonidine, B. Hydralazine, C. Nifedipine, D. Captopril
A: Clonidine
Answer: A: Clonidine 
Explanation: (Ref:KDT 6/e p546) Plasma renin activity is increased by reflex increase in sympathetic discharge. Clonidine decreases central sympathetic outflow and thus will decease the plasma renin activity. Vsodilators and ACE inhibitors result in reflex increase in plasma renin activity.