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
Tolazoline is used as: 
Select and explain. 
A. A thrombin inhibitor in peripheral angiography, B. A vasodilator in treating coronary artery stenosis during angio procedures, C. A vasoconstrictor in treatment of varices, D. An antispasmodic during biliary spasm
B: A vasodilator in treating coronary artery stenosis during angio procedures
Answer: B: A vasodilator in treating coronary artery stenosis during angio procedures 
Explanation: None