This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': 'A patient has carcinoma on the right side of anterior 2/3rd of the tongue with lymph node of size 4cm in level 3 on the left side of the neck. Stage of the disease is \nSelect and explain. \nA. N0, B. N1, C. N2, D. N3', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref: Dhingra 7e pg 306.', 'role': 'assistant'}]