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
True statement about listeria: 
Select and explain. 
A. Gram negative bacillus, B. Motile by peritrichous flagella, C. Commonest cause of community acquired meningitis, D. Only one serovar is known
B: Motile by peritrichous flagella
Answer: B: Motile by peritrichous flagella 
Explanation: Ans. is. 'b' i. e., Motile by peritrichous flagella