An airport has no tower, no FSS, and no UNICOM. Which frequency should a pilot use to self-announce?

1. 1121.5 MHz, the emergency frequency
2. 2122.75 MHz, the air-to-air frequency
3. 3123.45 MHz, the flight test frequency
4. 4122.9 MHz, the MULTICOM frequency

Source: Aeronautical Information Manual (FAA, Basic with Change 3, 9 July 2026), AIM 4-1-9 Traffic Advisory Practices at Airports Without Operating Control Towers, page 209