In Which Case Does the Nurse Act as "Whistle-Blower

In which case does the nurse act as "whistle-blower"?

A) One staff member on the unit covers for another nurse,who leaves the premises to purchase illegal substances.
B) The nurse reports that another nurse is taking medications out of stock medicine for herself or himself.
C) A nurse informs respiratory therapy that a patient is now due a treatment.
D) The nurse delegating care to unlicensed assistive personnel makes rounds to ensure all care was rendered properly.