What agency is primarily concerned with natural disaster response?

The correct choice is FEMA, which stands for the Federal Emergency Management Agency. This agency is specifically established to coordinate the federal government's response to natural disasters. Its primary mission is to support citizens and first responders while ensuring that the nation is prepared for, responds to, and recovers from disasters, including hurricanes, earthquakes, floods, and other widespread emergencies.

FEMA develops emergency management policies and offers assistance at the state and local levels to improve response capabilities. It provides resources, conducts training programs, grants, and works to ensure effective disaster preparedness and recovery throughout the nation. The role and focus of FEMA are explicitly directed towards disaster response and recovery, making it the leading agency in this area.

The other agencies involved in the options presented have different primary responsibilities. For instance, the FBI primarily handles federal law enforcement and investigations, while the CDC focuses on public health concerns and disease prevention. OSHA is dedicated to workplace safety and health regulations. Thus, their core functions do not center around managing natural disaster responses as directly as FEMA does.