This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
Which of the following is the national level system that provides annual national as well as state-level reliable estimates of feility and moality? 
Select and explain. 
A. Census, B. Adhoc Survey, C. Sample Registration System, D. Civil Registration System
C: Sample Registration System
Answer: C: Sample Registration System 
Explanation: Since civil registration is deficient in India, a Sample Registration System (SRS) was staed in the mid-1960s to provide reliable estimates of bih and death rates at the national and state level. SRS now covers the entire country and is a major source of health information. Since the introduction of this system, more reliable information on bih and death rates, age-specific moality and feility rates, infant and adult moality, etc. have been available