This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
[{'content': 'Root value of supinator jerk is \nSelect and explain. \nA. C3 C4, B. C4 C5, C. C5 C6, D. C8 T1', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref - Researchgate.net', 'role': 'assistant'}]