Which type of airspace is designated by a warning that may contain hazardous activities?

The correct answer is the type of airspace known as Warning Areas. These areas are specifically established over international waters or in areas that are outside the jurisdiction of a country, and they are designated to warn pilots that the airspace may contain hazardous activities, such as military exercises, live-firing operations, or other unsafe practices. The purpose of a warning area is to provide a precautionary measure for pilots to steer clear of potential hazards, ensuring safety while operating in or near these zones.

In contrast to warning areas, prohibited areas are strictly off-limits to all aircraft and are typically established for national security reasons. Restricted areas, while controlling access, may allow for some aircraft operations under specific conditions, but they require authorization before entering. Military Operations Areas (MOAs) indicate that military flight training may occur, but they do not necessarily signify hazardous activities in the same way that warning areas do. Understanding the distinctions among these types of airspace is crucial for pilots to navigate safely.