This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
Venous spread in carcinoma rectum reaches to the following structure 
Select and explain. 
A. Spleen, B. Kidney, C. Liver, D. Duodenum
C: Liver
Answer: C: Liver 
Explanation: Venous invasion has been considered a poor prognostic factor in rectal cancer for over half a century. This term has evolved in recent years and now applies specifically to tumor invasion into extramural veins - extramural venous invasion. This distinction from intramural venous invasion is impoant as it is more clinically relevant. Extramural venous invasion can be identified by histopathology and MRI but until recently there has been a lack of consistency in definitions and detection techniques.