Which of the following does NOT guarantee NAVAID signal reception or communications coverage?

The correct choice regarding which option does not guarantee NAVAID signal reception or communications coverage is OROCA.

OROCA stands for Minimum Off-Route Obstruction Clearance Altitude. It is primarily designed to ensure that aircraft remain clear of terrain and obstructions when flying off established airways, but it does not imply reliable signal reception from Navigation Aids (NAVAIDs) or communications facilities. OROCA is intended for obstacle clearance and does not consider the presence or quality of NAVAID signals.

On the other hand, Minimum Enroute Altitude (MEA), Minimum Alerting Altitude (MAA), and Minimum Reception Altitude (MRA) are all designed with the reliability of NAVAID signals in mind. MEA ensures adequate signal coverage for navigation while providing obstacle clearance. MAA defines the maximum altitude at which a NAVAID can reliably provide guidance, ensuring that aircraft remain within the range of the NAVAID signal. MRA ensures that an aircraft can receive the NAVAID signal, allowing for reliable navigation.

In summary, while MEA, MAA, and MRA provide assurance of navigation and communication coverage, OROCA's focus on obstruction clearance does not include provisions for NAVAID signal reception