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': 'Acid fast structure is: \nSelect and explain. \nA. Vibrio, B. Nocardia, C. E. coli, D. Bacillus anthracis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. b. Nocardia', 'role': 'assistant'}]