This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CHF, Angina Pectoris and Myocardial Infarction, Subject name: Pharmacology
Which of the following drugs is both aeriolar and venodilator? 
Select and explain. 
A. Hydralazine, B. Sodium nitroprusside, C. Minoxidil, D. Nitroglycerine
B: Sodium nitroprusside
Answer: B: Sodium nitroprusside 
Explanation: Group Effect in CHF Drugs Predominant aeriolar dilator Decrease afterload Hydralazine Predominant venodilator Decrease preload Nitrates Mixed dilator Decrease both preload and afterload Nitroprusside