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
[{'content': 'Poal vein is formed ? \nSelect and explain. \nA. Behind the spleen, B. Behind the tail of pancreas, C. Behind the neck of pancreas, D. Behind the second pa of duodenum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The poal vein is about 8 cm long.It is formed by union of superior mesenteric vein and splenic vein behind the neck of pancreas at the level of L2 veebrae in front of inferior vena cava (IVC).', 'role': 'assistant'}]