The federal agency responsible for disaster planning is the:

The Federal Emergency Management Agency (FEMA) is the agency specifically tasked with coordinating the federal government's response to natural and man-made disasters. FEMA is involved in disaster preparedness, response, recovery, and mitigation efforts. Its primary role is to ensure that the nation is adequately prepared for disasters, assist state and local governments in their planning efforts, and provide resources and support during emergencies.

FEMA develops comprehensive plans and resources to address various disaster scenarios, including floods, hurricanes, earthquakes, and terrorism. The agency also collaborates with other federal, state, and local entities to improve disaster response capabilities and create training programs to enhance public safety and resilience in the face of disasters. This makes it the most relevant and equipped agency for disaster planning at the federal level, unlike the other options, which do not focus solely on disaster management or response.