This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rectum and anal canal, Subject name: Surgery
In rectal carcinoma, distal margin should be at least: 
Select and explain. 
A. 2 cm, B. 3 cm, C. 4 cm, D. 5 cm
A: 2 cm
Answer: A: 2 cm 
Explanation: Tumor Margin For Curative Excision In GI malignancies (stomach, small intestine, colon and proximal rectum), tumor margin for curative excision is 5 cm except: Esophagus: 10 cm Distal rectum: 2 cm