This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Cilastatin is combined with which of the following to increase its duration? 
Select and explain. 
A. Carbenicillin, B. Cefoperazone, C. Imipenem, D. Penicillin G
C: Imipenem
Answer: C: Imipenem 
Explanation: Cilastatin inhibits renal dihydropeptidase enzyme that metabolizes Imipenem.