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
Treatment for CA Anal canal is 
Select and explain. 
A. Surgery, B. Surgery + Radiotherapy, C. Chemoradiation, D. Chemotherapy
C: Chemoradiation
Answer: C: Chemoradiation 
Explanation: Ca. Anal canal is treated by nigro’s regimen which is combine chemo + radiotherapy.