Which of the following statements is true?
earth's water is distributed evenly around the world.
ninety-five percent of the world's population has access to the water they need.
glaciers add to earth's groundwater and surface water sources.
economic scarcity happens when climate limits the amount of available water.

Option (c) is the correct answer.

Explanation:

Large and dense ice that moves due to its own mass is known as glaciers. When global warming increases then ice from the glaciers melt readily. As a result, this water goes into rivers, lakes, oceans etc.

Hence, there will be increase in surface water. But this water is also soaked by soil present on the ground. This leads to increase in level of ground water.

Therefore, we can conclude that the statement glaciers add to Earth's groundwater and surface water sources, is true.