**Core Concept**
The Reproductive and Child Health (RCH) programme in India utilizes a district-level approach to implement health interventions. This approach requires the division of districts based on specific criteria to ensure effective resource allocation and service delivery.

**Why the Correct Answer is Right**
Districts in the RCH programme are divided based on the population size, with a population of 10-20 lakhs in each district. This division is done to facilitate the planning and implementation of health services, including reproductive and child health services, at the district level. The district is considered the most appropriate administrative unit for the implementation of the RCH programme, as it allows for the effective coordination of health services with other development programmes.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the division of districts in the RCH programme.
* **Option B:** This option is incorrect as the RCH programme does not divide districts based on the literacy rate.
* **Option C:** This option is not a valid criterion for dividing districts in the RCH programme.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the RCH programme divides districts into three categories: A, B, and C, based on their population size, with A being the smallest and C being the largest. This categorization helps in the planning and implementation of health services at the district level.

**Correct Answer:** C.