This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Penicillin & Cephalosporin, Subject name: Pharmacology
[{'content': 'Drug of choice for tetanus: \nSelect and explain. \nA. Metronidazole, B. Penicillin, C. Erythromycin, D. Clindamycin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) MetronidasoleMust know points for tetanus (8th day illness presenting with lock jaw)* Penicillin G was considered the drug of choice, but some now consider metronidazole to be superior in this setting. Tetracycline is an alternative for patients who are allergic to penicillin or metronidazoleTetanus immunoglobulin is used to1. Prevent tetanus and to treat patients with circulating tetanus toxin and provides passive immunity.2. Treat all patients with active tetanus, in combination with other supportive and therapeutic treatments.', 'role': 'assistant'}]