What command is used to return an extended rectangular formation back to the original formation?

The command that is utilized to return an extended rectangular formation back to the original configuration is indeed "Assemble to the Right, March." This command instructs units to transition from an extended formation, where personnel are spread out in a rectangular shape, back to a more compact or traditional formation, typically aligning to the right of the formation leader.

In the context of military formations, ensuring that troops are organized correctly is vital for both efficiency and cohesion. The command specifically to "assemble" indicates bringing individuals together, while "to the right" directs them toward the right side, which is often a standard orientation for many military movements.

The other choices do not accurately describe the specific command needed for this transition. "Return to Line, March" generally refers to moving back to a straight line rather than a more compact formation from an extended format. "Form Up, Move" is often more about gathering troops without addressing the specific orientation. "Reassemble, Step Forward" may imply a gathering but lacks the specific instruction regarding the direction needed to return to the original alignment. Each of these alternatives, therefore, does not convey the precise action required to revert from an extended rectangular formation to the original formation effectively.