This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pleural effusion & Pulmonary alveolar proteinosis, Subject name: Medicine
[{'content': 'Pleural effusion in rheumatoid ahritis is typically associated with all of the following features except? \nSelect and explain. \nA. Glucose > 620 mg/dl, B. Protein> 3 gm/dl, C. Pleural fluid protein to serum protein ratio of > 0.5, D. Pleural fluid LDH to serum LDH ratio of >0.6', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Since Rheumatoid ahritis is an inflammatory disease, the rheumatoid effusion is an exudate and is known to have glucose of less than 60mg/dL. Malignancy and bacterial infections (empyema) can also present with low pleural fluid sugar.', 'role': 'assistant'}]