During ____________, the Joint Force Commander will identify the operational problems to solve and determine where to focus the staff's efforts.

The correct choice is mission analysis, which is a critical phase in the joint operation planning process. During mission analysis, the Joint Force Commander and the staff conduct a comprehensive assessment of the operational environment, including threats, capabilities, and available resources. This phase is crucial because it helps to clearly outline the operational problems that need to be addressed.

In this stage, the commander gathers and synthesizes information to identify objectives and key tasks. This analysis not only focuses on the challenges in the operational environment but also on determining the most effective approach to achieving the mission's goals. By pinpointing where to concentrate the staff's efforts, the commander establishes a clear direction for planning and execution.

Understanding this phase is essential in joint military operations, as it sets the groundwork for developing strategies and plans that align with the commander’s intent and the overall mission objectives.