Which EICAS messages cannot be paged?

The ability to page EICAS (Engine-Indicating and Crew-Alerting System) messages is dependent on their severity and type. In the context of EICAS, warnings are critical alerts that require immediate attention and action from the flight crew. These warnings display vital information related to system malfunctions or abnormal conditions that could lead to significant safety concerns.

Advisory messages, on the other hand, provide important but less urgent information regarding the aircraft's systems. While they are crucial for situational awareness, they do not represent immediate threats that require instant action.

In the case presented, both warnings and advisories cannot be paged. This means that once these messages are displayed on the EICAS, they remain visible and cannot be replaced by other information through paging. The system is designed this way to ensure that critical information remains constantly accessible to the crew. This constant availability ensures that pilots are always aware of the critical status of the aircraft, allowing them to respond appropriately without losing sight of essential warnings and advisories.

Therefore, the reasoning behind the correct answer encompasses the design intention of the EICAS to prioritize safety and maintain visibility on messages that are essential for safe aircraft operation.