The Major Presence of Water Detected on the Moon Is

The major presence of water detected on the Moon is in

A) the puffs of steam seen coming from some still active lunar volcanoes.
B) the flows of mud seen on the walls of some craters.
C) the floors of deep craters in the polar regions, as ice deposits that never thaw.
D) the mare.
E) faint clouds of ice in the thin lunar atmosphere.