What does the airfield encompass?

The correct answer highlights that the airfield encompasses operations and maintenance venues for aircraft. The airfield is specifically designated for aircraft operations, which includes the areas where airplanes take off, land, and are serviced. This includes not only the runways and taxiways but also the hangars and maintenance facilities that support aircraft readiness and safety.

By focusing on operations and maintenance, this choice emphasizes critical aspects of airport functionality that directly relate to the airfield's purpose. While passenger check-in areas, lounges, restaurants, and shops play essential roles in the airport experience, they are not part of the airfield but rather serve terminal functions. Similarly, the definition of the airfield excludes only the runway and taxiway systems, as it includes much more related to the support and management of aircraft operations.