How can all aircraft ensure consistent DME mileages?

Stating "DME" when communicating allows all aircraft to ensure a consistent reference for distance measuring equipment (DME) readings. This distinct call indicates that the aircraft is using DME for navigation and distance measurements, which helps air traffic control and other aircraft understand the context of the distance being reported. All aircraft equipped with DME will be synchronizing their distance reporting based on the same equipment and standards, promoting consistent DME mileages across the board.

Other options might involve aspects that do not directly impact or standardize the distance readings from DME. For instance, reporting altitude or speed does not affect the way DME calculates distances, as DME focuses primarily on horizontal distances to and from stations, rather than vertical measurements or variations in speed. Reporting positions at regular intervals, while helpful for maintaining situational awareness, doesn't inherently standardize the DME mileage, as DME relies on signals transmitted between the aircraft and the ground-based station.