This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci), Subject name: Microbiology
[{'content': "A 7year old boy presented to the OPD with complaints of pain and discharge from left ear. On examination the patient was febrile with neck rigidity and positive Kernig's sign. Gram positive cocci were visualised in the gram stained specimen of the discharge.Most likely pathogen is? \nSelect and explain. \nA. Streptococcus pneumoniae, B. Staphylococcus aureus, C. Haemophilus influenzae, D. Staphylococcus epidermidis", 'role': 'user'}, {'content': 'Answer: A \nExplanation: The history and clinical features are suggestive of otitis media with meningitis. Pneumococci are the most common cause of otitis media in children. Excluding of the other options: Haemophilus influenzae is a gram negative bacilli Staphylococcus aureus and Staphylococcus epidermidis are not commonly implicated in the causation of otitis media.', 'role': 'assistant'}]