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': 'Most common tumor to produce metastasis to cervical lymph nodes - \nSelect and explain. \nA. Glottic Ca, B. Nasopharyngeal carcinoma, C. Ca Base of tongue, D. Ca lip', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans is "b" i.e. Nasopharyngeal carcinoma Note: Glottic carcinoma never metastasizes to lymph nodes and carcinoma lip metastasizes rarely and very late', 'role': 'assistant'}]