This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerve Injuries - 1, Subject name: Orthopaedics
[{'content': "Brachial plexus injury with Horner's syndrome, nerve root level involved is : \nSelect and explain. \nA. C5, B. C6, C. C7, D. T1", 'role': 'user'}, {'content': 'Answer: D \nExplanation: - Horner syndrome is due to involvement of white matter of spinal cord at T1 level." Klumpke\'s palsy: Occurs in lower trunk of brachial plexus (C8-T1) Claw hand is present due to the paralysis of intrinsic muscles of hand It is associated with Horner\'s syndrome Has poor prognosis', 'role': 'assistant'}]