This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
[{'content': 'A young female presents with symptoms and signs of meningitis. CSF shows gram-positive bacilli. The most likely causative agent is? \nSelect and explain. \nA. Listeria monocytogenes, B. Haemophilus influenzae, C. Pneumococcus, D. Pseudomonas', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Listeria monocytogens are gram-positive bacilli.Haemophilus influenzae and Pseudomonas are Gram negative.Pneumococcus is capsulated gram-positive cocci in pairs.', 'role': 'assistant'}]