Imipenem,a newer antibiotic with a broad antibacterial spectrum,is coadministered with cilastin because:

• A. The combination of these antibiotics is Synergistic against Pseudomonas species
• B. Cilastin aids the gastrointestinal absorption of the active moiety,imipenem
• C. Cilastin inhibits a Beta-lactamase that destroys imipenem
• D. Cilastin inhibits an enzyme in the kidney that destroys imipenem