This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
Left anterior descending artery is a branch of: 
Select and explain. 
A. Right coronary artery, B. Left coronary artery, C. Ascending aorta, D. Coronary sinus
B: Left coronary artery
Answer: B: Left coronary artery 
Explanation: Ans. B Left coronary arteryRef: Gray's Anatomy Review E-book, P 80Left anterior descending artery is a branch of left coronary artery.