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: Anatomy
[{'content': 'All the veins in the following drain to a Common structure except \nSelect and explain. \nA. Great cardiac Vein, B. Anterior cardiac Vein, C. Middle cardiac Vein, D. Vein of Marshall', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Anterior cardiac Veins directly drain into left atrium, rest all drain to Coronary sinus.', 'role': 'assistant'}]