After a Client's Discharge from the Critical Care Unit to the Step-Down

After a client's discharge from the critical care unit to the step-down unit after a myocardial infarction, the nurse assesses the client carefully during sleep because

A) anxiety relative to the recent myocardial infarct may cause sleep disorders.
B) apnea is more common immediately after myocardial infarction.
C) breathing abnormalities may result in hypoxia.
D) REM rebound may occur, placing greater demands on the heart.