During a WAAS GPS approach, what does an LNAV+V annunciation indicate?

The LNAV+V annunciation during a WAAS GPS approach indicates that advisory vertical guidance is provided during descent. This feature enhances the approach by providing pilots with vertical guidance similar to an Instrument Landing System (ILS), although it is important to note that this guidance is not as precise or mandatory as the guidance provided by an ILS.

With LNAV+V, pilots can benefit from enhanced situational awareness and better decision-making by following the advised vertical profile during the approach. It helps maintain a smoother descent profile and can assist pilots in managing their approach more effectively, especially in instances where vertical guidance might not otherwise be available.

The other options suggest either a requirement for altitude decisions, performing approaches without guidance, or signal unavailability, which do not accurately represent what LNAV+V signifies. In summary, LNAV+V is a valuable feature for providing advisory vertical guidance, aiding the pilot in achieving a safer and more efficient approach.