Answer : 1. "Ocean"
Explanation :

The river is the source of fresh water. Freshwater can be found in glaciers, lakes, reservoirs, ponds, rivers, streams, wetlands and even groundwater. Out of all the water on Earth, just 3% is fresh water. About three-quarters of Earth's freshwater is stored in glaciers. Therefore, glacier ice is the second largest reservoir of water on Earth and the largest reservoir of freshwater on Earth! Hence we can say that Ocean is not a source of fresh water.