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': "Ridley's scale is used in classification of which disease? \nSelect and explain. \nA. Tuberculosis, B. Malaria, C. Leprosy, D. Measles", 'role': 'user'}, {'content': "Answer: C \nExplanation: Ridley's logarithmic scale is used to grade the response to treatment in case of leprosy. Ref: Park 21st edition, page 293.", 'role': 'assistant'}]