This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Normal poal vein pressure is 
Select and explain. 
A. < 3 mm Hg, B. 3-5 mm Hg, C. 5-10 mm Hg, D. 10 to 12 mm of Hg
C: 5-10 mm Hg
Answer: C: 5-10 mm Hg 
Explanation: Poal veins carries approximately 75% of blood supply to the liver, formed by the junction of the superior mesenteric and splenic veins behind neck of pancreas&;s Normal poal vein pressure is 5-10mmHg if there is sustained elevation in the poal venous pressure more than 10mmHg. Reference SRB edition :5 page:614