What Is Responsible for the Difference in the Bulbocavernosus (BC)

What is responsible for the difference in the bulbocavernosus (BC) muscles between male and female rats?

A) In both males and females the spinal motor neurons connect to BC muscle and both sexes expresses androgen receptors, but only in males do androgens promote motor neuron development and survival of the muscle.
B) In both males and females the spinal motor neurons connect to BC muscle but only males express androgen receptors, thus only in males do circulating androgens promote motor neuron development and survival of the muscle.
C) In females the spinal motor neurons do not connect to BC muscle and thus androgen receptors cannot promote motor neuron development so the muscle degenerates.
D) Motor neurons of the spinal nucleus of the bulbocavernosus (SNB) are not present in females, so BC muscle never forms.