Which command is given first when transitioning from a normal line formation to an extended rectangular formation?

The command to transition from a normal line formation to an extended rectangular formation is "Extend to the left, March." This command is essential because it initiates the movement of troops to widen the formation, allowing the unit to spread out laterally. In the context of military formations, transitioning to an extended rectangular formation is often necessary to increase the frontage for various operational needs, such as establishing a perimeter or preparing for a more expansive area of engagement.

The command emphasizes the action of moving to the left, which is critical because it guides the personnel in their movement and ensures that they do so in a coordinated manner. This aligns the soldiers properly into the new formation, maintaining the overall discipline and order of the unit.

The other commands provided do not serve this specific function in the context of changing formations. While commands like "Right, Face" and "From front to rear count, Off" have their places in drill and military procedures, they are not applicable to the specific transition of formations in this scenario. The command "Arms downward, Move" pertains to adjusting individual positions rather than the collective movement of the formation. Thus, "Extend to the left, March" is the correct and effective choice for achieving the desired formation change.