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: Anatomy
The hepatic poal vein is formed by the union of which of the following major vessels? 
Select and explain. 
A. Superior Mesenteric and Inferior Mesenteric Veins, B. Superior Mesenteric and Splenic Veins, C. Superior Mesenteric And left renal vein, D. Inferior Mesenteric and Splenic Vein
B: Superior Mesenteric and Splenic Veins
Answer: B: Superior Mesenteric and Splenic Veins 
Explanation: The hepatic poal vein is formed by the union of, (a) Splenic vein, which drains the spleen, pancreas, greater curvature of stomach, and (b) Superior mesenteric, which drains the small intestine andascending colon. The gastric vein, which drains the lesser curvature of the stomach, empties directly into the hepatic poal vein.