This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Arterial Disorders, Subject name: Surgery
[{'content': 'Coronary graft is most commonly taken from? \nSelect and explain. \nA. Femoral vein, B. Saphenous vein, C. Axillary vein, D. Cubical vein', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Saphenous veinRefi: Introductory Guide to Cardiac Catheterization- Arman T. Askari, Medhi H. Shishehbor, Ronnier J. Aviles 159', 'role': 'assistant'}]