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': 'Staphylococcal pathogenicity is indicated by- \nSelect and explain. \nA. Coagulase positivity, B. Hemolysis, C. Lipoteichoic acid, D. Endotoxin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Virulence factors of Staphylococcus aureus\n\nThere are numerous virulence factors responsible for the pathogenicity of staph aureus, but the most consistent association of virulence is the production of coagulase and to a lesser extent, fermentation of mannitol.\nCoagulase causes activation of prothrombin and leads to fibrin formation around the bacteria, protecting the bacteria from phagocytosis.', 'role': 'assistant'}]