This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
[{'content': "Adson's test is positive in \nSelect and explain. \nA. Cervical rib, B. Cervical fracture, C. Cervical spondylosis, D. Cervical dislocation", 'role': 'user'}, {'content': "Answer: A \nExplanation: Adson's sign is the loss of the radial pulse in the arm by rotating head to the ipsilateral side with extended neck following deep inspiration . Ref : S. Das surgery 3/e p641", 'role': 'assistant'}]