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: Ophthalmology
[{'content': 'Tetracycline ointment for mass prophylaxis – \nSelect and explain. \nA. 0.10%, B. 0.50%, C. 1%, D. 5%', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In blanket antibiotic therapy, the regimen is to apply 1% tetracycline eye ointment twice daily for 5 days in a month for 6 months.', 'role': 'assistant'}]