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. Nifedipine, C. Hydralazine, D. Clonidine
D: Clonidine
Answer: D: Clonidine 
Explanation: None