**Core Concept**
The Sample Registration System (SRS) is a dual record system used for estimating vital statistics, such as birth and death rates, in India. It involves continuous enumeration of births and deaths by an enumerator and a supervisor, as well as a periodic survey by a medical officer.

**Why the Correct Answer is Right**
The SRS is considered a robust method for estimating vital statistics as it combines the strengths of both continuous enumeration and periodic surveys. The dual record system helps to reduce errors and biases in reporting vital events, such as births and deaths. The SRS also allows for the estimation of fertility and mortality rates at the national and sub-national levels.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the Sample Registration System.
**Option B:** This option is incorrect as the SRS is not a single-record system.
**Option C:** This option is incorrect as the SRS does not rely solely on administrative data.

**Clinical Pearl / High-Yield Fact**
The SRS is a valuable tool for public health planning and policy-making in India, providing accurate estimates of vital statistics that inform decisions on healthcare and population growth.

**Correct Answer: C. It relies on dual record system.**