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: Medicine
[{'content': 'Which of the following is not seen in Chronic Regional Pain Syndrome? \nSelect and explain. \nA. Anhydrosis, B. Pain, C. Swelling, D. Osteoporosis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Complex regional pain syndrome is usually associated with increased sweating (hyperhydrosis) and not anhydrosis. Pain and swelling are features of CRPS, while osteoporosis may present with CRPS. So the single best answer of choice is anhydrosis. Ref: Harrison's Principles of Internal Medicine, 16th Edition, Page 2433", 'role': 'assistant'}]