The amount of Earth covered by water might imply that all water is a renewable resource. Which statement best explains why not all water is renewable?

A. Most water on Earth is salt water, and salt water is not a renewable resource.
B. Only 1 percent of water on Earth is drinkable, which makes this water limited.
C. Fresh water is evenly distributed around the world.
D. About one-third of all freshwater is frozen in the polar ice caps.