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
Nitroglycerine exerts beneficial effects in variant angina primarily by: 
Select and explain. 
A. Coronary vasodilation, B. Decreased ventricular contractility, C. Reduction of cardiac preload, D. Reduction of cardiac afterload
A: Coronary vasodilation
Answer: A: Coronary vasodilation 
Explanation: None