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': 'The middle cardiac vein is located at the: \nSelect and explain. \nA. Anterior interventricular sulcus, B. Posterior interventricular sulcus, C. Posterior AV groove, D. Anterior AV groove', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Posterior interventricular sulcus vein & posterior interventricular br. of right coronary aery is located in poster inter ventricular sulcus Q', 'role': 'assistant'}]