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': 'Staphylococcus is \nSelect and explain. \nA. Gram - positive cocci, B. Gram - negative cocci, C. Gram - positive bacillus, D. Gram - negative bacillus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Gram positive bacteria \n\nThere are 6 classic gram-positive bacteria that cause human disease.\n\n\nOf these 2 are cocci\n\n\nStaphylococci\nStreptococci (including anaerobic peptostreptococci)\n\n\nOther 4 are bacilli\n\n\nCorynebacterium\nBacillus\nClostridium\nListeria', 'role': 'assistant'}]