What are composed of forces from two or more military departments and have a broad continuing mission?

The correct answer is unified combatant commands. These commands are established to integrate the efforts of multiple military branches, such as the Army, Navy, Air Force, and Marines, to achieve a common objective. They operate under a single commander and are designed to manage diverse operations across various regions or functional areas, providing a coordinated response to military needs.

Unified combatant commands have broad, continuing missions and are organized to be strategically agile, responding to large-scale military operations, peacetime engagements, and humanitarian assistance. This structure allows for effective resource allocation and unified planning among different service branches.

While joint task forces consist of forces from two or more military departments, they are typically formed for a specific, temporary mission and do not possess the ongoing authority or broad mission scope typical of unified combatant commands. Coalition forces involve partnerships with allied nations, whereas command structures refer more generally to hierarchical arrangements within a military organization, lacking the specific interdepartmental coordination of unified combatant commands.