Final answer:
406 MHz Emergency Locator Transmitters (ELTs) should be registered with the FAA before being put into service or testing, as part of aviation safety protocols.
Step-by-step explanation:
The question asks to identify the organization with which all 406 MHz Emergency Locator Transmitters (ELTs) must be registered before they are put into service or tested. The correct answer is that 406 MHz ELTs should be registered with the FAA (Federal Aviation Administration) before being put into service or testing.
It's important for aircraft owners and operators to register their ELTs with the FAA to ensure that in the case of an emergency, search and rescue teams can quickly identify and assist the aircraft in distress. This is a crucial step for aviation safety and adherence to regulations.