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': "'Obstruction of Inferior vena cava' presents : \nSelect and explain. \nA. Paraumblical dilatation, B. Thoraco-epigastric dilatation, C. Oesophagus varies, D. Haemorrhoides", 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Thoraco-epigastric dilation', 'role': 'assistant'}]