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
[{'content': 'Most common cause of malignant poal vein thrombosis is: \nSelect and explain. \nA. Renal cell carcinoma, B. Carcinoma prostate, C. Hepatocellular carcinoma, D. Carcinoma colon', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Malignancies are responsible for 21%-24% of overall cases of PVT. Among them hepatoma accounts for majority followed by pancreatic malignancy. PVT is common in patients affected by liver cirrhosis. Ref: World J Gastroenterol 2010 January 14; 16(2): 143-155.', 'role': 'assistant'}]