This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anal Malignancy, Subject name: Surgery
[{'content': 'Commonest type of Anal canal Ca is : \nSelect and explain. \nA. Sq. cell Ca, B. Adeno Ca, C. Adenoacanthoma, D. Papillary type', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' ie Squamous cell Ca Mainly 3 types of malignant neoplasm are seen in anal canalSquamous cell Ca (MC)Basal cell Ca (IInd me)MelanomaRememberMC type of rectal & colon Ca - Adenocarcinoma*.", 'role': 'assistant'}]