During Its Months-Long Hibernation in Its Burrow,the Body Temperature of an Arctic

During its months-long hibernation in its burrow,the body temperature of an Arctic ground squirrel

A) is held at a constant 37°C.
B) is held at a constant 0°C.
C) varies between 0°C and 37°C, depending on the frequency of arousals from hibernation.
D) varies between 0°C and 15°C, depending on the external temperature outside of the burrow.
E) varies between 0°C and +5°C, depending on the temperature in the burrow.