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
The middle cardiac vein is located at the - 
Select and explain. 
A. Anterior interventricular sulcus, B. Posterior interventricular sulcus, C. Posterior AV groove, D. Anterior AV groove
B: Posterior interventricular sulcus
Answer: B: Posterior interventricular sulcus 
Explanation: In Coronary sulcus
-        Great cardiac vein, small cardiac vein, coronary sinus, right coronary artery, left circumflex artery
 In anterior interventricular sulcus
-        Great cardiac vein, left anterior descending artery
 In posterior interventricular sulcus
-        Middle cardiac vein, posterior interventricular branch of right coronary artery