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: Microbiology
[{'content': 'Anti streptolysin 0 test is diagnostic in - \nSelect and explain. \nA. Acute rheumatic fever, B. SLE, C. SBE, D. Rhematoid ahritis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Acute rheumatic fever . ASO titres higher than 200 are indicative of prior streptococcal infection. High levels are usually found in acute rheumatic fever.", 'role': 'assistant'}]