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
[{'content': 'Nitroglycerine exerts beneficial effects in classical angina pectoris primarily by: \nSelect and explain. \nA. Increase in total coronary blood flow, B. Redistribution of coronary blood flow, C. Reduction of cardiac preload, D. Reduction of cardiac afterload', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]