In Rats, Freezing

In rats, freezing

A) is often a maladaptive response to fearful stimuli, since fighting or fleeing are more useful in most situations.
B) is accompanied by analgesia only when the response allows escape from the fear-inducing stimulus.
C) can be accompanied by the release of endorphins, particularly when the fear-inducing stimulus can produce pain.
D) is slow to condition because it competes with the tendency to flee or fight.