What type of airspace may contain hazards to nonparticipating aircraft in international airspace?

In international airspace, warning areas are specifically designated to inform pilots of potential hazards to nonparticipating aircraft. These areas are established to indicate that there may be activities that could pose dangers, such as military exercises, live munitions testing, or other activities that might not be visible or recognizable to pilots not involved in those operations.

While restricted areas and prohibited areas certainly also pose dangers, they are typically used for more specific operational reasons and have restrictions that may not directly apply in the broader context of international airspace. Restricted areas require permission for entry, while prohibited areas do not allow any entry at all. However, warning areas serve as a notification mechanism for pilots flying in the vicinity that they should be cautious due to potential hazards, even if they are not formally restricted from entering.

Class B airspace, on the other hand, pertains mainly to the management of commercial air traffic around busy airports and does not inherently indicate hazards relevant to nonparticipating aircraft like a warning area does. Therefore, the characteristics and purpose of warning areas make them the correct choice in identifying potential hazards in international airspace for nonparticipating aircraft.