Describing a Physiological Variable as "Homeostatic" Means That It

Multiple Choice

Describing a physiological variable as "homeostatic" means that it

A) has varied from the normal value,and will remain constant at the new value.
B) never varies from an exact set point value.
C) is in an equilibrium state that requires no energy input to stay at the normal value.
D) is in a state of dynamic constancy that is regulated to remain near a stable set point value.
E) has no normal range,but will just change to match the outside environmental conditions.