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
Ridley's scale is used in classification of which disease? 
Select and explain. 
A. Tuberculosis, B. Malaria, C. Leprosy, D. Measles
C: Leprosy
Answer: C: Leprosy 
Explanation: Ridley's logarithmic scale is used to grade the response to treatment in case of leprosy. Ref: Park 21st edition, page 293.