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: Surgery
[{'content': 'Radical dissection of neck includes all except - \nSelect and explain. \nA. Cervical lymph nodes, B. Sternocleido mastoid, C. Phrenic nerves, D. Internal jugular vein', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]