What type of airspace encompasses a warning area extending from U.S. shores?

The correct answer is international airspace. A warning area is specifically designated to inform pilots of activities that may be hazardous, often involving military exercises, and it typically extends from the U.S. shoreline into international waters.

International airspace, by definition, generally refers to airspace that is not under the jurisdiction of any one country and exists outside the territorial limits of national airspace. The nature of a warning area, which includes activities occurring over water and beyond U.S. territorial limits, aligns it with international airspace. Controlled airspace and restricted airspace relate to areas with specific regulatory requirements for air traffic, while uncontrolled airspace is generally applicable to areas with fewer restrictions, but none of these classifications accurately describe the unique characteristics of a warning area that extends from U.S. shores into the broader international realm.