## Core Concept
The National Water Supply and Sanitation Programme (NWSSP) aims to provide safe drinking water and sanitation facilities to rural areas. A "problem village" is a designation used to identify villages facing significant challenges in accessing safe drinking water.

## Why the Correct Answer is Right
The correct answer, , indicates that a problem village is one where there is a **scarcity of drinking water** or the **available water is highly contaminated**. This definition aligns with the goals of NWSSP to prioritize areas with limited access to safe drinking water.

## Why Each Wrong Option is Incorrect
* **Option A:** This option is incorrect because it does not accurately reflect the definition of a problem village according to NWSSP.
* **Option B:** This option is incorrect because it also does not accurately describe the criteria for a problem village.
* **Option C:** This option is incorrect as it likely presents an alternative definition not aligned with NWSSP's focus on water scarcity and contamination.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the designation of a "problem village" helps in **prioritizing interventions** for water supply and sanitation. This is crucial for **preventing water-borne diseases** and improving public health in rural areas.

## Correct Answer Line
**Correct Answer: D.**