This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Surgery
[{'content': 'Best treatment strategy for carcinoma anal canal: \nSelect and explain. \nA. Chemoradiation, B. Surgery, C. Radiation, D. Chemotherapy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nowadays the primary treatment of choice is chemoradiotherapy (Combined modality therapy (CMT); Nigro Regimen), which usually includes 5-FU, Mitomycin-C and cisplatin Radical surgery is indicated in those with persistent or recurrent disease following CMT or Nigro Regimen.', 'role': 'assistant'}]