Which of the following is NOT a type of defensive operation?

The correct answer identifies "Raid Defense" as the option that does not represent a type of defensive operation. In military terminology, defensive operations are categorized primarily into area defense, mobile defense, and retrograde defense.

Area defense involves securing a designated area against enemy forces, focusing on holding ground and defending fixed positions. Mobile defense revolves around the principle of using maneuver warfare to operate in a more flexible manner, often involving a withdrawal to conserve forces or draw the enemy into a pre-prepared area of engagement. Retrograde defense entails operations where forces withdraw in an organized manner to maintain combat effectiveness while reducing losses during retreats.

In contrast, a "Raid" is primarily an offensive operation intended to disrupt, destroy, or gather intelligence on enemy forces, rather than a defensive posture. It typically involves a quick incursion into enemy-held territory with limited objectives and is not characterized by the defensive nature that the other options encompass. Thus, recognizing the characteristics of each operation type helps in understanding why "Raid Defense" does not belong in the context of defensive operations.