Without Authorization, a Nurse Administers an Extra Dose of Narcotic

Without authorization, a nurse administers an extra dose of narcotic tranquilizer to an agitated client. The nurse's coworker observes this action but does nothing for fear of retaliation. What is the ethical interpretation of the coworker's lack of involvement?

A) Taking no action is still considered an unethical action by the coworker.
B) Taking no action releases the coworker from ethical responsibility.
C) Taking no action is advised when potential adverse consequences are foreseen.
D) Taking no action is acceptable, because the coworker is only a bystander.