This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Orthopedics, Subject name: Surgery
[{'content': "Allen's test is used to diagnose: \nSelect and explain. \nA. Thoracic outlet syndrome, B. Palmar arch insufficiency, C. Superior vena cava syndrome, D. Coarctation of aorta", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ref: Bailey and One's Short Practice of Surgery 25th EditionExplanation:Allen's testIt is a test for the patency of the radial artery after insertion of an indwelling monitoring catheter. The patient's hand is formed into a fist *nd the ulnar artery is compressedcompression continues while the fist is opened.If blood perfusion through the radial artery is adequate, the hand should Hush and resume its normal pinkish coloration.Adsonks testIt is the loss of the radial pulse in the arm by- rotating head to the ipsi lateral side with extended neck following deep inspiration.It is seen in thoracic outlet syndrome (TOS)", 'role': 'assistant'}]