How Does Staying Underground in a Burrow During the Day

How does staying underground in a burrow during the day help a kangaroo rat conserve water?

A) They're safer from predators and can go out and drink at night.
B) It's too hot in a desert for any mammal to be out during the day at all.
C) The food absorbs moisture from the ground and the rats get extra water that way.
D) Their exhalation in the burrow keeps the humidity high, the food absorbs that water, and they thereby recycle some of the water they lose through respiration
E) Because they each have their own "territory" in a burrow, they don't have to compete for water there.