This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
Which of the following is a vinodilator? 
Select and explain. 
A. Hydralazine, B. Minoxidil, C. Nitroprusside, D. Nifedipine
C: Nitroprusside
Answer: C: Nitroprusside 
Explanation: Ref:Katzung 10/e p173-174;KDT 6/e p540 Hydralazine, minoxidil and nifedipine are primarily aerioler dilators where as nitroprusside is a mixed aerioler and venous dilator, therefore best answer here seems to be nitroprusside