Which body is responsible for coordinating the Federal response until a Joint Field Office is established?

The correct answer is the Regional Response Coordination Centers, which play a crucial role in managing and coordinating the federal response to disasters before the establishment of a Joint Field Office. These centers function as vital links between federal resources and local or state emergency management agencies during the initial stages of disaster response.

Their primary responsibility includes facilitating the deployment of federal assistance, coordinating logistical support, and ensuring that the needs of affected communities are met efficiently. They act as a command and control structure that can mobilize federal resources quickly in response to an incident, thereby streamlining communication and operational effectiveness at the onset of disaster recovery efforts.

In contrast, other choices like the State Emergency Management Agency are typically focused on state-level disaster response and coordination. The Federal Bureau of Investigation's role centers around law enforcement and national security issues, rather than disaster response coordination. National Guard Units, while instrumental in providing support during emergencies, are often coordinated through state entities rather than triaging initial federal efforts prior to a Joint Field Office being set up.

The Regional Response Coordination Centers are essential for ensuring that the federal response is effective and timely, filling the gap until a more permanent response structure can be established.