Answer:
O B. 70 percent
Step-by-step explanation:
Of total freshwater, over 70 percent is locked up in ice and glaciers. Another 30 percent of freshwater is in the ground. Rivers are the source of most of the fresh surface water people use, but they only constitute about 509 mi3 (2,120 km3), about 1/10,000th of one percent of total water.
Note: Percentages may not sum to 100 percent due to rounding.