This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neoplastic Disorders, Subject name: Surgery
[{'content': 'Most common cancer of anus? \nSelect and explain. \nA. Squamous, B. Basaloid, C. Cuboidal, D. Cloacogenic', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) SquamousRef.: Bailey & Love 26th ed. /1267', 'role': 'assistant'}]