51. Amphotericin B and polymyxin interfere with

A. cell wall synthesis
B. protein synthesis
C. cell membrane function
D. DNA function

52. Which of the following is not β-lactamase-resistant penicillin?

A. Oxacillin
B. Nafcillin
C. Carbenicillin
D. Methicillin

53. The antibiotics which afford a broad spectrum of antimicrobial coverage against aerobic and anaerobic bacteria, rickettsiae, chlamydiae, and mycoplasmas is

A. gentamicin
B. tetracycline
C. metronidazole
D. vancomycin