This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
[{'content': 'Most common infection in patients with prosthetic valves within one month of Surgery: \nSelect and explain. \nA. Pneumococcus, B. Pseudomonas, C. Staphylococcus aureus, D. Enterococci', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. Staphylococcus aureusStaphylococci and streptococci can account for majority of Infective endocarditis.* Staphylococcal infective endocarditis is more common in healthcare associated infective endocarditis cases and it accounts for more than half of infective endocarditis cases.* Streptococci remains common cause of community acquired infective endocarditis.* Injection drug use endocarditis is more common in young males and it affects the right side of the heart.* The tricuspid valve is involved more commonly than the pulmonary valve.', 'role': 'assistant'}]