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': 'Treatment for CA Anal canal is \nSelect and explain. \nA. Surgery, B. Surgery + Radiotherapy, C. Chemoradiation, D. Chemotherapy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ca. Anal canal is treated by\xa0nigro’s regimen which is combine chemo + radiotherapy.', 'role': 'assistant'}]