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: Pathology
[{'content': 'Causative organism in acute bacterial endocarditis is - \nSelect and explain. \nA. Staphylococcus aureus, B. Streptococcus viridans, C. Pneumococcus, D. Streptococcus pyogenes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Acute osteomyelitis\xa0may be : -\n\ni. Primary (hematogenous):- Organisms reach the bone through the bloodstream.\nii. Secondary:- Organism gain energy directly through wound such as in compound fractures or\xa0surgical operation,\n\nHematogenous osteomyelitis\xa0is the commonest form of osteomyelitis\xa0and most common source of bone\xa0and joint infection\xa0is hematogenous.\nit is caused most commonly by Staphylococcus aureus.\nOther causative\xa0organisms are streptococcus, pneumococcus, and gram-negative\xa0bacilli.', 'role': 'assistant'}]