Which of the following is an example of controlled airspace?

Controlled airspace refers to airspace in which the operations of aircraft are subject to specific regulatory controls to promote safe flying conditions. Class B airspace is indeed an example of controlled airspace, as it surrounds the busiest airports and requires pilots to obtain clearance from air traffic control before entering. This extensive traffic management helps maintain separation between aircraft in high-density environments, ensuring safety and efficiency.

In contrast, Class G airspace is considered uncontrolled, meaning that it does not have the same level of regulatory oversight, and pilots do not need to communicate with air traffic control when operating in this type of airspace. Class C and Class D airspace are also forms of controlled airspace; however, the question specifically asks for an example, and Class B airspace is the most prominent form due to its extensive regulations and clearance requirements at major airports.