Sustainment in joint operations refers to:

• A. The planning and execution of logistics and support to maintain operations.
• B. The use of all weapon systems to achieve effects on targets.
• C. Measures to preserve the force and mission by reducing risk and increasing survivability.
• D. Delegating authority to subordinates to execute tasks.

Answer: (A)

Sustainment in joint operations is about keeping the force effective by delivering the logistics and support needed to continue the mission. It centers on planning and executing the supply chain to provide what the troops need—fuel, ammunition, food, spare parts, medical care, maintenance, transportation, and personnel services—so operations can persist at the required tempo. It also covers maintaining equipment, arranging distribution, and ensuring forces can redeploy or sustain themselves over time. This focus on the continuous flow of resources and services is what keeps operations moving, even as conditions on the ground change.

The other ideas describe different functions: using weapon systems to achieve targets relates to fires or effects, not sustainment; preserving the force by reducing risk and increasing survivability points to protection and risk management; delegating authority to subordinates is about command and control. Sustainment provides the logistical backbone that enables all of those activities to happen.