Which statement best describes the concept of unified command?

The concept of unified command is best described by the statement that representatives from different agencies share command authority. Unified command is a structure used during incidents that involve multiple agencies, often in complex or large-scale emergencies such as natural disasters, hazardous material spills, or large fires. This approach allows for a cohesive strategy and coordination among the various organizations involved.

In unified command, each agency retains its authority while collaborating on decision-making processes, ensuring that everyone works toward the same goals and objectives despite their distinct responsibilities. This model fosters cooperation, resource sharing, and a coordinated response, which enhances overall incident management effectiveness.

The other options do not accurately capture the essence of unified command. While having a command staff or a clearly defined chain of command can be important in certain contexts, the unique aspect of unified command is the shared authority among different agencies, which is crucial for effective incident management across diverse groups.