What mode must the link be in during the flight?

During a flight, the appropriate mode for personal electronic devices is typically "Airplane mode". This setting is essential as it disables the device's cellular functions to prevent any interference with the aircraft's communication and navigation systems. However, many airlines now allow the use of Wi-Fi during the flight, provided the device is in Airplane mode first.

Choosing "Flight mode with Wi-Fi on" indicates that the device remains compliant with regulations while also allowing passengers the convenience of internet access through the airplane's Wi-Fi network. This combination ensures that the aircraft’s systems remain undisturbed while still providing connectivity options for passengers.

The other possibilities would not align with current aviation regulations where the combination of functionality needed is clearly defined for safety and operational efficiency.