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: Medicine
Staphylococcus aureus and pneumoniae are responsible for: 
Select and explain. 
A. Subacute endocarditis., B. Acute endocarditis., C. Post operative endocarditis., D. None.
B: Acute endocarditis.
Answer: B: Acute endocarditis. 
Explanation: None