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': 'A female patient with signs of meningitis and CSF showing gram positive coccobacilli, which is showing characteristic tumbling motility. Diagnosis is - \nSelect and explain. \nA. Listeria, B. Meningococcus, C. H. influenzae, D. Pneumococcus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]