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': 'All are increased in rheumatoid arthritis, except \nSelect and explain. \nA. ESR levels, B. Rheumatoid factor, C. Anti-CCP Antibodies, D. Synovial fluid viscosity', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]