This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Most common agent causing tuberculosis in AIDS patient in tropical countrie is - \nSelect and explain. \nA. Mycobacterium tubercolusis, B. Mycobacterium intracellulare, C. Mycobacteriumparvum, D. Mycobacterium atypical', 'role': 'user'}, {'content': "Answer: A \nExplanation: In the USA and other Western countries the characteristic pathogen now is M.tuberculosis. REF:ANANTHANARAYAN AND PANIKER'S TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO-576", 'role': 'assistant'}]