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
In sample registration system independent survey is done at every 
Select and explain. 
A. 2 months, B. 6 months, C. 12 months, D. 2 years
B: 6 months
Answer: B: 6 months 
Explanation: SRS is a dual record system initiated to provide reliable estimates of bih and death rates.It consists of a continuous enumeration of bihs and deaths by an enumerator and an independent survey every 6 months by an investigator-supervisor.Park 23e pg: 841