The correct option is (c).
Explanation
The distribution of water on Earth is highly uneven. While water covers a vast portion of the planet's surface, the specific availability of freshwater for human consumption is limited by its physical state and location.
Analysis of Water Distribution:
- Total Global Water: Approximately 97.3% of all water on Earth is saline (oceans and seas) and is not fit for drinking or agriculture.
- Freshwater Reserves: Only about 2.7% to 3% of the total water is freshwater.
- Breakdown of Freshwater:
- Ice Caps and Glaciers: The majority of this freshwater (approximately 68% to 70%) is locked in permanent ice sheets in Antarctica, Greenland, and high mountain regions. This portion is technically "fresh" but is inaccessible for direct human use.
- Groundwater: Approximately 30% of freshwater is stored underground.
- Surface Water: Only about 1% of freshwater is easily accessible in rivers, lakes, and the atmosphere.
Justification of the Correct Option:
Option (c) correctly identifies that the primary reason the bulk of freshwater is unavailable is that it exists as frozen ice sheets and glaciers.
Key Takeaway:
Of the Earth's total freshwater, the largest portion is trapped in glaciers and ice caps, making it inaccessible. Consequently, only a tiny fraction (approx. 1%) exists as readily available surface water.