This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
Sullivan index is an index for 
Select and explain. 
A. Life free of disability, B. Life Expectancy, C. Earning capacity, D. Population index
A: Life free of disability
Answer: A: Life free of disability 
Explanation: Sullivan's index also known as Disability Free Life Expectancy (DFLE) is a method to compute life expectancy free of disability. It is calculated by formula:Life expectancy minus duration of disability Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 26