Final answer:
A Tactical Directive is a direct order issued by an Incident Safety Officer to immediately address an imminent threat, backed by the authority of the Incident Commander.
Step-by-step explanation:
The answer is C) Tactical Directive. A tactical directive can be defined as a direct order to immediately stop, alter, suspend or withdraw personnel, activities, and operations due to an imminent threat. The intervention by an Incident Safety Officer (ISO) takes the form of an official order that carries the full authority of the Incident Commander (IC) to back it up.