This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Chemoprophylaxis with tetracycline is useful in which of the following? \nSelect and explain. \nA. Cholera, B. Brucellosis, C. Meningococcemia, D. Plague', 'role': 'user'}, {'content': "Answer: A \nExplanation: Cholera: Tetracycline or furazolidone for household contacts Bacterial conjunctivitis: Erythromycin ophthalmic ointment Diphtheria: Erythromycin Influenza: Oseltamivir Meningitis, meningococcal: Ciprofloxacin, and minocycline Plague: Tetracycline for contacts of pneumonic plague Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 137", 'role': 'assistant'}]