This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': 'Recurrent or residual cancer of nasopharynx after super voltage radiotherapy is treated by: \nSelect and explain. \nA. Intracavitary radioactive implants, B. Cryotherapy, C. Surgery, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: If nasopharyngeal carcinoma recurs or is not completely regressed after 6500-7000 cGy radiotherapy, it can be treated by any of the above modes. Surgery involves skull-base and is done in only selected cases.', 'role': 'assistant'}]