## Core Concept
The classification of villages based on the depth of water is crucial for assessing water accessibility and planning water resource management. A problem village is typically defined based on the depth at which water can be accessed.

## Why the Correct Answer is Right
A problem village is generally considered to be one where the water table is at a depth of more than 150 feet. This classification is significant because it indicates areas where accessing groundwater is difficult and might require deeper drilling or alternative water sourcing strategies. The depth of 150 feet is a benchmark used in various contexts to differentiate between easily accessible water and water that requires more effort to obtain.

## Why Each Wrong Option is Incorrect
* **Option A:** 50 feet - This is considered a safe and easily accessible depth for water, not typically classified as a problem village.
* **Option B:** 100 feet - While deeper than 50 feet, this is still within a range where accessing water might not be extremely challenging, depending on the local hydrogeology.
* **Option D:** 200 feet - Although this is also a significant depth, the specific classification of a problem village is tied to the 150 feet benchmark.

## Clinical Pearl / High-Yield Fact
A critical point to remember is that the classification of a problem village based on water depth can vary by region and specific criteria used by organizations or governments. However, 150 feet is a commonly referenced threshold.

## Correct Answer: C. 150 feet.