This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Pharmacology
[{'content': 'Which of the following antimicrobial shows time dependent killing? \nSelect and explain. \nA. Ofloxacin, B. Amikacin, C. Penicillin, D. Ciprofloxacin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Bactericidal agents can be divided into two groups: Agents that exhibit concentration-dependent killing (e.g. aminoglycosides and quinolones) Agents that exhibit time-dependent killing (e.g., b lactams and vancomycin).', 'role': 'assistant'}]