What type of system does the A320's AC power receptacle support?

The A320's AC power receptacle is specifically designed to support the avionics power supply. This system is critical because the avionics on an aircraft require reliable power to operate various electronic systems essential for navigation, communication, and flight management. The AC power receptacle allows for external power sources to provide the necessary electrical power for the avionics when the aircraft is on the ground, ensuring that all systems are operational and can be tested or updated prior to flight.

In the context of the other options, jet fuel management primarily concerns fuel systems and is not directly related to electrical power. The staff communication system relies on different types of communication technology, which would not directly use the AC power receptacle for its operation. Lastly, while the engine starter system does require electrical power, it typically operates on DC power rather than AC and is more relevant to the aircraft's engine start procedure than to the general avionics function supported by the AC receptacle.