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': 'One of the following infections is caused by anaerobic gram-positive cocci - \nSelect and explain. \nA. Puerperal infection, B. Food poisoning, C. Endocarditis, D. Septicemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]