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: Medicine
Which of the following values indicate normal poal venous pressure? 
Select and explain. 
A. 5 - 10 mm Hg, B. 10 - 15 mm Hg, C. 20 - 25 mm Hg, D. 25 - 30 mm Hg
A: 5 - 10 mm Hg
Answer: A: 5 - 10 mm Hg 
Explanation: Normal poal venous pressure is 5 - 10mmHg (10 - 15cm saline). Poal venous system contributes 75% of blood and 72% of oxygen supplied to the liver. Poal vein is formed by the confluence of superior mesenteric vein and splenic vein. In an average adult 1000-1500ml /min of poal venous blood is supplied to the liver. Reference: Schwaz's Principles of Surgery 9e chapter 31.