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 commonest variation in the arteries arising from the arch of aorta is - \nSelect and explain. \nA. Absence of brachiocephalic trunk, B. Left vertebral artery arising from the arch, C. Left common carotid artery arising from brachiocephalic trunk, D. Presence of retroesophageal subclavian artery', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]