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': 'In extended supraomohyoid neck dissection, lymph node dissection is done upto: \nSelect and explain. \nA. 2, B. 3, C. 4, D. 5', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]