The Emergency Department Nurse Manager Is Explaining Concepts of Emergency

The emergency department nurse manager is explaining concepts of emergency and disaster preparedness to a group of students.Which statement by the nurse manager is most accurate?

A) "An internal disaster is something that occurs inside the health care facility."
B) "An external disaster occurs when someone not employed here disrupts our operations."
C) "A multi-casualty event involves disasters at several different locations."
D) "The Joint Commission requires that we participate in a disaster drill once a year."