The correct option is A 2.5
About 97.5% of the water available on earth is found in seas and oceans
as saline water and is not available to us for use directly. Only 2.5%
of the total water resources of the world consist of fresh water.
Majority of it is frozen in the ice caps at the two poles and on
snow-covered mountains. Only limited amount of fresh water is available
to us as a renewable resource through water cycle but its distribution
is uneven. So, the correct answer is '2.5'.