This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Vein of Mayo is seen at? 
Select and explain. 
A. Saphenous junction, B. Pylorus, C. Colon, D. Brain
B: Pylorus
Answer: B: Pylorus 
Explanation: Pre-pyloric vein of Mayo is a tributary of the right gastric vein that passes veically anterior to the pylorus at its junction with the duodenum. It has rectal tributaries. Right gastric vein drains into the poal vein. (Reference: BDC Volume 2 : Large blood vessels of gut)