What must the cabin lights be set to during an evacuation preparation at landing?

During an evacuation preparation at landing, the cabin lights must be set to bright. This setting ensures that passengers can clearly see their escape routes and any potential obstacles in the cabin when they need to exit the aircraft quickly. Bright lighting is essential for safety and orientation during an emergency situation, allowing passengers to navigate effectively and reducing the risk of accidents as they prepare to evacuate.

In contrast, dim or off settings would hinder visibility, making it difficult for passengers to find their way to the exits, while flashing lights are typically used for alerting and signaling rather than for guiding passengers during an evacuation. Consequently, having the lights set to bright is a critical safety measure during this preparation phase.