The largest amount of freshwater on our planet is available for us is form

Freshwater includes ice caps, rivers, ponds, streams, glaciers, swamps, icebergs, and even groundwater. Freshwater does not contain seawater. 

Two-thirds of the world is made up of water.  Almost 68% of the world's freshwater is in the polar regions in the form of ice caps and glaciers. 30% of the world's water is underground. 0.3% water can be found in lakes, streams, rivers and ponds. 
Therefore, the correct answer to this question is option B. Polar ice caps and glaciers.