Which facility is responsible for receiving and relaying all pertinent ELT signal information to the appropriate authorities?

The facility that is responsible for receiving and relaying all pertinent Emergency Locator Transmitter (ELT) signal information to the appropriate authorities is the Air Route Traffic Control Center (ARTCC). ARTCCs play a crucial role in the national airspace system by managing air traffic services and ensuring safety during flight operations.

When an ELT signal is detected, the ARTCC is equipped to analyze and process the information. They then coordinate with various agencies, such as search and rescue teams, to initiate a response to the emergency. This capability is essential for ensuring timely assistance and safety for the aircraft and its occupants.

In contrast, while other options like Air Traffic Control (ATC) and Flight Service Stations may interact with ELT signals, their primary functions do not encompass the direct management and relaying of ELT information in the same way that ARTCCs fulfill. The Flight Standards District Office (FSDO) primarily deals with regulatory aspects of aviation safety and does not handle ELT signal operations. Therefore, the ARTCC's dedicated role makes it the correct answer for this question.