Which statement about enroute descents is true?

The statement that pilots must initiate enroute descents is accurate. In the context of flight operations, while air traffic controllers may suggest or request descents, the ultimate responsibility for initiating the descent lies with the pilots. They evaluate the flight parameters, traffic, and operational requirements to determine when to commence the descent. This vigilance is crucial as pilots must adhere to safety standards and ensure the aircraft is at the proper altitude for approaches and landings.

Enroute descents are not obligatory and do not always occur, depending on the flight plan and conditions; hence the other options do not accurately reflect the processes and responsibilities involved in enroute descents.