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': 'Organism most likely to cause "fever of unknown origin" in a farmer who raises goats - \nSelect and explain. \nA. Brucella melitensis, B. Clostridium novyi, C. Histoplasma capsulatum, D. Mycobacterium tuberculosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Brucella melitensis infection is acquired from goat sheep and camels.', 'role': 'assistant'}]