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
All of the following bacteria shows bipolar staining except? 
Select and explain. 
A. Y pestis, B. H influenza, C. Fransciella, D. Pastuerella
B: H influenza
Answer: B: H influenza 
Explanation: H.ducreyi shows bipolar staining whereas H.influenza doesnot.