What is the primary unit that should be established when the number of Divisions exceeds the Incident Commander's span of control?

When the number of Divisions in an incident exceeds the Incident Commander's span of control, establishing Branches is the appropriate course of action. The concept of span of control refers to the optimal number of individuals that can be effectively supervised by a single leader, which is generally recognized as being around three to seven individuals. When the complexity of an incident increases, and the number of Divisions escalates beyond what the Incident Commander can manage effectively, dividing the responsibilities further into Branches allows for a more manageable structure.

Each Branch can then oversee multiple Divisions, thereby streamlining communication and ensuring that operations can be conducted efficiently without overwhelming any single leader. This hierarchical system enhances coordination and facilitates better resource deployment, ultimately improving the overall management of the incident.

The other options, while relevant to the incident command structure, do not serve this specific purpose as effectively as Branches do in terms of managing an expanded operational workload. Groups and Divisions refer to different organizational units within the command structure, and Sections typically relate to broader functional areas such as Operations, Planning, Logistics, and Finance, rather than specifically addressing the issue of control with Divisions.