How Should the Nurse Advise Parents Whose Preschooler Used to Sleep

How should the nurse advise parents whose preschooler used to sleep through the night and now awakens at intervals after a short hospitalization?

A) Regressive behavior after a hospitalization is normal and usually short term.
B) The child is probably expressing anger.
C) Egocentric behavior often manifests itself when the child is left alone to sleep.
D) The child is probably feeling pain and needs further evaluation.