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': 'The largest branch of brachial plexus is ? \nSelect and explain. \nA. Ulnar, B. Medial, C. Radial, D. Axillary', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The radial nerve is the largest branch of the posterior cord of the brachial plexus with a root value of C5-C8, T1. Ref: BD Chaurasia; Volume I; 7th edition; Page no: 57.', 'role': 'assistant'}]