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: Surgery
[{'content': 'Pain in varicose vein is due to all except \nSelect and explain. \nA. Increased venous wall tension, B. Increased capillary permeability, C. Hyperviscosity of RBCs, D. Hypoxia of tunica media of venous wall', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In varicose veins, there is decreased capillary permeability causing capillary functional disorder.', 'role': 'assistant'}]