If the RMU passes the preflight test, what will it display?

When the RMU (Remote Multi-function Unit) passes the preflight test, it will display the preflight test page for a duration of 5 seconds. This is an indication that the system has successfully completed all necessary checks and is functioning properly before the aircraft is operated. The display of the preflight test page serves as a confirmation for the pilot that the RMU is operational and ready for use. This brief display ensures that the pilot is aware of the system's readiness and can proceed with their preflight preparations confidently.

In contrast, the other options represent scenarios that do not accurately describe the outcome of a successful preflight test. A checklist of all systems might be part of the operational procedures but is not specifically used as an indicator of the RMU's status after the test. Displaying the current UHF frequency would take place under normal operations, rather than indicating test results. Lastly, an error message would be a result of a failed preflight test, signaling that the RMU requires attention or troubleshooting rather than displaying a successful result.