Question ATPL - Airline Transport Pilot license - Radio Navigation

In relation to the satellite navigation system NAVSTAR/GPS, 'All in View' is a term used when a receiver: - ATPL

Is receiving the signals of all visible satellites but tracking only those of the 4 with the best geometric coverage

Is receiving and tracking the signals of all 24 operational satellites simultaneously

Is tracking more than the required 4 satellites and can instantly replace any lost signal with another already being monitored

The aircraft's receiver measuring the phase angle of signals received from a number of satellites in known positions