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

• A. Area Defense
• B. Ambush Defense
• C. Retrograde Defense
• D. Mobile Defense

Answer: (B)

The key idea here is how defense is organized in military doctrine. Defensive operations are categorized by the overall approach to holding and maneuvering, not by standalone ambush tactics. The standard types describe how forces are arranged and how they respond to an attack: defending a defined area to deny enemy access and control that space; using mobile defense to trade space for time and defeat the attacker through flexible maneuver; and retrograde defense to purposefully withdraw, reposition, or reduce forces to preserve combat power for future operations. An ambush, while a valuable tactical technique used within various defense actions, is not itself a formal category of defensive operation type. So a designation like “Ambush Defense” isn’t listed as a recognized defensive operation type, making it the correct choice for not being an official category.