This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': "The following pathogen does not satisfy 'Koch's postulates'- \nSelect and explain. \nA. Bacillus anthrax, B. Mycobacterium tubercolosis, C. Clostridium tetani, D. Lepra bacilli", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Mycobacterium leprae is ble but not culturable. That cannot be isolated in cell-free culture. Can be grown in the footpad of mice.It is a long and strenuos process REF:Textbook of Microbiology, Ananthanarayan, and Paniker. Page no.: 346, 364', 'role': 'assistant'}]