Which of the following are the two categories of airspace in the NAS?

The correct categories of airspace in the National Airspace System (NAS) are primarily classified as controlled and uncontrolled. Controlled airspace is where air traffic control (ATC) services are provided to regulate aircraft operations and ensure safe separation between them. This includes airspace classes A, B, C, and D, where specific rules and requirements apply for operating within those structures.

Uncontrolled airspace, on the other hand, is where ATC services are not mandated, allowing pilots to operate with more freedom, typically found in Class E and G airspace. Pilots operating in uncontrolled airspace are still expected to follow certain regulations, such as maintaining visual separation from other aircraft, but they are not required to communicate with air traffic control.

While the option mentioning regulatory and non-regulatory might seem relevant, it does not accurately reflect the primary categorization of airspace that most affects operations in the NAS. The focus on controlled versus uncontrolled is essential for understanding how different airspaces function and how air traffic management is achieved within them.