Which statement accurately differentiates bacteriostatic and bactericidal antibiotics and explains a common mechanism for antagonism between them?

• A. Bactericidal drugs inhibit protein synthesis while bacteriostatic drugs always damage membranes; antagonism occurs because membrane damage increases the apparent MIC of the cidal drug by enhancing efflux.
• B. Bacteriostatic drugs kill cells only during stationary phase, while bactericidal drugs are effective only during lag phase; combining them always leads to synergy because they act at different times.
• C. Bacteriostatic drugs inhibit growth without killing, while bactericidal drugs kill actively growing cells; using a bacteriostatic drug can prevent growth-dependent killing by a bactericidal drug, producing antagonism.
• D. Bacteriostatic drugs irreversibly block cell wall synthesis and therefore potentiate bactericidal drugs that target ribosomes, which exclusively explains antagonism between unrelated drug classes in all bacterial species.

Answer: (C)