Which of the following is considered controlled airspace?

Controlled airspace is defined as airspace in which air traffic control (ATC) services are provided to pilots. This encompasses several classifications of airspace, including Class A, Class B, Class C, Class D, and Class E. Each class has specific operational requirements and rules that govern its use.

Class B airspace surrounds busy airports and requires pilots to receive ATC clearance before entering, ensuring safe operations in high-traffic areas. Class C airspace encompasses airports with a moderate amount of traffic and also requires ATC clearance, but has less stringent requirements compared to Class B.

While Class B and Class C airspace are indeed types of controlled airspace, all classes of airspace, including Class A and Class D, also fall under this category. Therefore, indicating that only Class B and Class C airspace can be considered controlled airspace restricts the definition inappropriately.

The correct answer recognizes the definitions and operational characteristics of controlled airspace as encompassing more than just specific classes.