Which of the following is NOT a type of Defensive Task?

The correct choice is the one that identifies the task that does not fall under the category of defensive operations. The term "Exploitation" refers to a type of offensive operation that involves taking advantage of the enemy's weaknesses and pursuing them aggressively, often after a successful attack has created an opening.

In contrast, Area Defense, Mobile Defense, and Retrograde are all recognized types of defensive operations. An Area Defense focuses on defending a specific geographical area, a Mobile Defense includes maneuvering forces to counterattack against an enemy while maintaining a strong hold on certain positions, and a Retrograde task involves organized withdrawal from an enemy force while retaining the capability to fight effectively.

By understanding the distinctions between these operations, it becomes clear why exploitation is categorized differently, as its primary aim is to capitalize on the momentum gained from an offensive action rather than aiming to hold or defend positions against enemy forces.