Which display shows the FMS's current mode during an approach?

The Primary Flight Display (PFD) is key in providing essential flight information, particularly during critical phases like an approach. One of its primary functions is to present the aircraft's flight path and current flight mode, which includes the Flight Management System (FMS) mode in use.

When executing an approach, the PFD shows critical information such as altitude, airspeed, and vertical speed, along with the current mode of the FMS which indicates how the aircraft is configured for landing tasks. This mode display is vital for the pilot to understand how the aircraft is being controlled and which phase of the approach is active, such as approach mode or go-around mode.

On the other hand, while the Multi-Function Display (MFD) can show various informative data including navigation and other system status, it does not primarily convey the FMS's current mode as directly as the PFD does. The Engine Indication Display (EID), as its name suggests, focuses on engine performance metrics and does not provide flight mode information. Lastly, the Navigation Display (ND) is more concerned with the mapping and routing details rather than directly indicating the specific FMS mode during approaches.

Thus, the PFD is the correct choice because it is specifically