Explanation: Inmarsat GMDSS terminals require watch officers to program certain operational parameters. When initiating a "hot-key" Distress Alert, the system transmits the alert via a pre-selected Land Earth Station (LES). The choice of LES, which is typically configured by the watch officer in the Distress Alert Update menu, is crucial because each LES is linked to specific Rescue Coordination Centers (RCCs) responsible for particular maritime search and rescue regions. Therefore, selecting the correct LES ensures the distress alert is routed to an appropriate and operational ground station, which can then efficiently forward it to the relevant RCC responsible for coordinating assistance in the vessel's area. Options B and C are incorrect because while GPS provides the vessel's position *within* the distress message, it does not automatically update or change the *selected* LES for routing the alert. The initial routing choice to an LES is typically a manual operator selection. Option D is incorrect because while manufacturers set initial defaults, effective GMDSS operation requires ongoing operator configuration and verification of critical settings like LES selection, which are not automatically updated for distress routing.