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': 'Paget-Schroetter syndrome is \nSelect and explain. \nA. Primary lower limb DVT, B. Primary upper limb DVT, C. Femoral vein compression, D. Pelvic vein compression', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Primary upper limb deep vein thrombosis is Paget Schroetter syndrome is due to subclavian vein compression that occurs in thoracic outlet syndrome.', 'role': 'assistant'}]