Task organization is a ______ grouping of forces designed to accomplish a particular mission.

Task organization refers to the arrangement of forces specifically structured to achieve a defined mission or objective. The correct answer is "relatively permanent" because this type of organization is established to provide the necessary capabilities and resources for a particular operation, while it may adapt to changing needs or mission requirements.

This means that units can be reassigned or modified as necessary based on the nature of the task at hand. However, the structure itself remains more enduring than a purely temporary organization, indicating a commitment to a specific mission rather than a fleeting arrangement. The term 'relatively' acknowledges that while the organization is firm during the mission, it is subject to change as new missions or priorities arise, aligning with the dynamic nature of military operations.