What class of airspace extends from the surface to 4,000 feet MSL?

The correct answer indicates that Class C airspace extends from the surface to 4,000 feet MSL. Class C airspace is typically found surrounding airports that have a significant volume of traffic and is designed to ensure safe operations around those airports. This class of airspace generally encapsulates controlled airspace where air traffic control services are provided for all aircraft, regardless of whether they are operating instrument or visual flight rules.

Class C airspace usually consists of two layers: a core area that extends from the surface to a specified altitude (which, in many cases, is 4,000 feet) and an outer area that typically begins at an altitude of 1,200 feet above the surface. The purpose of this structure is to manage and facilitate efficient air traffic operations, reducing the likelihood of midair collisions.

In contrast, Class B airspace typically extends from the surface up to 10,000 feet MSL surrounding major airports, Class D airspace extends from the surface up to 2,500 feet around smaller airports, and Class E airspace typically begins at 1,200 feet MSL and can extend up to 18,000 feet where it interfaces with Class A airspace. Understanding these distinctions is important for pilots and air traffic