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
Abdomino-perineal resection is done in colorectal Ca on the basis of - 
Select and explain. 
A. Age of patient, B. Distance from anal-verge, C. Fixity of tumor, D. Hepatic metastasis
B: Distance from anal-verge
Answer: B: Distance from anal-verge 
Explanation: None