This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': "True statement about antistreptolysin 'O' titer is \nSelect and explain. \nA. In normal people the titre is > 200, B. In acute glomerulonephritis the titre is low, C. ASO titre > 200 indicate rheumatic fever, D. It is poorly antigenic", 'role': 'user'}, {'content': "Answer: B \nExplanation: ASO (Anti Streptolysin 'O') titer:Estimation of antibody against streptolysin is a standard serological test for retrospective diagnosis of streptococcal infectionASO titer> 200 is indicative of prior streptococcal infectionRaised after throat infection onlyIn acute glomerulonephritis the titer is low", 'role': 'assistant'}]