What is the maximum airspeed allowed within 4 NM of a primary airport inside Class D airspace at or below 2,500 feet AGL?

The maximum airspeed allowed within 4 nautical miles of a primary airport inside Class D airspace at or below 2,500 feet AGL is indeed 200 knots indicated airspeed (KIAS). This regulation is in place to manage the flow of aircraft in busy airspace around airports, ensuring safe separation and minimizing the potential for turbulence or wake encounters.

Class D airspace typically denotes the airspace around airports where air traffic control (ATC) services are provided. In this environment, reducing speed to 200 KIAS is crucial because it enhances safety for both arriving and departing aircraft, enabling better coordination and more predictable traffic patterns.

The options that reflect higher speeds, such as 250 KIAS and 300 KIAS, would not be suitable for the dense traffic typically found in the vicinity of primary airports. Additionally, while the 150 KIAS option is allowed in some other contexts, it does not specifically apply to the defined airspace requirements surrounding Class D airports. The 200 KIAS limit strikes a balance between operational efficiency and safety, which is why it is the correct answer.