What is a major operational advantage of Mode S selective interrogation over traditional Mode A/C SSR systems in high-density airspace?

1. It eliminates garbling and transponder saturation by interrogating only specific aircraft using their unique 24-bit address.
2. It allows the radar to track aircraft without any onboard transponder installation.
3. It increases the range of the radar to over 500 NM.
4. It automatically corrects altimeter settings on board the aircraft.