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': 'A patient has carcinoma of tongue in the right lateral aspect with lymph node of 4 cm size in level 3 on the left side of neck, what is the stage ? \nSelect and explain. \nA. N0, B. N1, C. N2, D. N3', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]