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: Orthopaedics
[{'content': 'Stellate ganglion block is useful in- \nSelect and explain. \nA. Sudeck osteodystrophy, B. Compound palmar ganglion, C. Tenosynovitis, D. Osteoarthritis of first CMC joint', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sympathetic nerve block is used in RSD :- Stellate ganglion block for upper extremity RSD and L1\xa0- L3 block for lower extremity.', 'role': 'assistant'}]