What does the Air Defense Identification Zone (ADIZ) encompass?

The Air Defense Identification Zone (ADIZ) is a designated area of airspace over land or water, established for the purpose of identifying and controlling aircraft, particularly those entering the airspace of a sovereign nation, such as the United States. The primary purpose of the ADIZ is national security, allowing military and civilian authorities to track all aircraft in the zone.

The correct choice indicates that the ADIZ encompasses airspace surrounding the US coast and over Washington D.C. This is accurate because the ADIZ is specifically designed to monitor and control potential threats from airborne entities approaching the United States. Within these zones, all aircraft must identify themselves and their intent, enabling the military to respond as necessary to any unauthorized or suspicious activity.

In contrast, the other options do not accurately describe the ADIZ. For instance, airspace with no radar does not typically correspond with the ADIZ, as radar is a critical component in monitoring these highly sensitive areas. International airspace is outside a country's territorial control, making it much different from the controlled environment of an ADIZ. Lastly, Class B airspace pertains to specific airspace around major airports and does not encompass the broader national security focus that the ADIZ represents.