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': 'Decreased glucose level in pleural effusion is found in -a) Rheumatoid arthritisb) SLEc) Pneumococcal infectiond) P.carinii infection \nSelect and explain. \nA. a, B. bc, C. ac, D. b', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]