This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerves of Upper Extremity, Subject name: Anatomy
[{'content': 'Root of radial nerve: \nSelect and explain. \nA. C6,C7,T1, B. C5,C6,C7,T1, C. C5,C6,C7,C8,T1, D. C4,C5,C6,C7,C8,T1', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) C5, C6, C7, C8, T1Ref: BDC 6th ed. vol. I / 55-56', 'role': 'assistant'}]