Correct Option: C

Even though most of the Earth's surface is water, only 1% of it is fresh usable water. Ninety-seven percent of the Earth's water is saltwater, which contains too many minerals for humans to use untreated. Two percent of our water is "locked up" in ice caps and glaciers, leaving only one percent as usable fresh water. Groundwater comprises 0.62 per cent of water, followed by Freshwater Lakes: 0.009 per cent; and rivers: 0.0001 per cent.