What is the correct GPS entry when instructed by ATC to "expect the GPS approach to runway 30"?

When ATC instructs a pilot to "expect the GPS approach to runway 30," the primary focus is on loading the specific approach into the aircraft's GPS system. This involves inputting the approach procedure into the navigation system so that it can provide the necessary lateral and vertical guidance as the aircraft prepares to land. By only loading the approach, the pilot ensures that they have the correct and updated flight path for the approach to runway 30, which will facilitate a safe and accurate landing.

The other options, while potentially relevant in different contexts, do not directly address the immediate requirement presented in the instruction from ATC. Activating the autopilot may or may not be necessary at that moment depending on the flight situation, and reviewing departure procedures is not pertinent since the instruction is specifically for an approach to a runway, not a departure. Setting the frequency is also important but is secondary to ensuring the approach is loaded and ready for navigation. Therefore, loading the approach is the essential step in responding to the ATC instruction effectively.