This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
[{'content': 'An 18-year-old man who is known to have non penicillinase producing gonococcal urethritis is given an injection of penicillin and probenecid. What is the mechanism used by probenecid that makes penicillin more efficacious \nSelect and explain. \nA. Promotes entry of the penicillin into the bacteria, B. Prolongs the duration of action by affecting the liver metabolism of penicillin, C. Decreases the bacterial resistance by inhibiting penicillinase production, D. Increases the half-life and serum level by decreasing the renal excretion of penicillin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Probenecid decreases the renal excretion of penicillin, thereby increasing both the half-life and the serum level. Ref:- KD Tripathi', 'role': 'assistant'}]