For aircraft coming from sector 45 requesting FL180, what should the student issue?

When an aircraft requests FL180, the appropriate response from air traffic control is to issue a usable altitude. A usable altitude means that the requested altitude is one that can be safely assigned and is appropriate given the current air traffic, weather conditions, and airspace structure.

In this context, it is crucial for the controller to assess the traffic situation and any other operational considerations, and then provide an altitude that the pilot can safely ascend to. If FL180 is available and meets the spacing and separation requirements, issuing a usable altitude allows for the smooth integration of the aircraft into the airspace.

The other options, such as issuing a delay in departure or a different flight path, do not directly address the altitude request and may be warranted only under specific circumstances, such as congestion or airspace restrictions. A warning about turbulence, while possibly important for pilot safety, does not substitute the need to respond to the altitude request effectively. Thus, providing a usable altitude directly responds to the pilots’ request and maintains operational efficiency.