Which areas are explicitly not allowed for flight?

The correct answer is that prohibited areas are explicitly not allowed for flight. Prohibited areas are designated airspace within which no person may operate an aircraft, except for those who have special permission from the appropriate authorities, such as the military or governmental agencies. These areas are established for reasons of national security, safety, or to protect specific ground facilities or activities, ensuring that aircraft do not inadvertently enter these zones, which could pose a risk to both aircraft and the associated ground operations.

Other airspace classifications, while they have specific restrictions or considerations, do not carry a blanket prohibition on all flights. For instance, restricted areas may have certain operational limitations, but they often allow authorized flights under particular circumstances. Warning areas are similar in that they depict areas where there may be hazardous activities, but flights may still occur if the appropriate caution is exercised. Class B airspace is designed to manage the high levels of traffic found at major airports and allows specific types of flight operations under established regulations, not a total prohibition.