36 Freshwater is a more precious commodity than many people in the developed world recognize. More than 97 percent of Earth’s
water is salty, unfit for drinking. Of the remainder, more than two-thirds is frozen in glaciers and icecaps, leaving just 1
percent of all the water on our planet fresh. About one one-hundredth of that 1 percent resides in rivers and other waterways;
the rest is beneath the earth's surface. Pressure on this invaluable resource is growing.
In the last sentence, the phrase “this invaluable resource” most probably refers to _____.
(A) fresh water (B) water unfit for drinking (C) people in the developed world (D) frozen glaciers and icecaps