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': 'All of the following bacteria shows bipolar staining except? \nSelect and explain. \nA. Y pestis, B. H influenza, C. Fransciella, D. Pastuerella', 'role': 'user'}, {'content': 'Answer: B \nExplanation: H.ducreyi shows bipolar staining whereas H.influenza doesnot.', 'role': 'assistant'}]