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
All are morbidity indicators execpt - 
Select and explain. 
A. Period of stay in hospital, B. Doctor : population ratio, C. Attendance at out patient depament, D. Notification rates
B: Doctor : population ratio
Answer: B: Doctor : population ratio 
Explanation: Ans. is `b' i.e., Doctor : population ratio Health change cannot be measured in specified unit. o So, different indicators have been defined which reflect health change in a community. o These indicators are called health indicators e.g. moality indicators, morbidity indicators, Disability rates.