A 60-year-old man who underwent prosthetic aortic valve replacement 3 months ago develops fever, chills, and a new systolic murmur. Blood cultures grow *Staphylococcus aureus*. What is the most appropriate initial empiric antibiotic regimen for presumed prosthetic valve endocarditis?

✓ Correct Answer: Option C

Early prosthetic valve endocarditis (within 1 year of surgery) is often caused by *Staphylococcus* species. The recommended empiric regimen is a combination of antibiotics, typically vancomycin (for MRSA coverage), gentamicin (synergistic effect), and rifampin (to penetrate biofilm).