A Mother of a 1-Month-Old Infant Asks the Nurse Why

A mother of a 1-month-old infant asks the nurse why it takes so long for infants to learn to roll over.The nurse knows that the reason for this is that:

A) there must be a demyelinating process occurring with her infant.
B) myelin is needed to conduct the impulses, and the neurons of a newborn are not yet myelinated.
C) the cerebral cortex is not fully developed, so control over motor function occurs gradually.
D) the spinal cord is controlling the movement because the cerebellum is not yet fully developed.