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: Social & Preventive Medicine
[{'content': 'Dose of Chloroquine when used for Chemoprohylaxis of Malaria is \nSelect and explain. \nA. 300 mg twice/week, B. 600 mg once/week, C. 300 mg Once/week, D. 600 mg/week', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]