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
A female patient with signs of meningitis and CSF showing gram positive coccobacilli, which is showing characteristic tumbling motility. Diagnosis is - 
Select and explain. 
A. Listeria, B. Meningococcus, C. H. influenzae, D. Pneumococcus
A: Listeria
Answer: A: Listeria 
Explanation: None