To obtain Double Arms Interval in a line formation from normal interval, what command is required?

To achieve Double Arms Interval in a line formation from a normal interval, the command "Take Interval to the Left, March" is the required command. This command instructs the Marines to increase the distance between them to a position that provides more room when the arms are extended, ensuring that they have enough space without crowding.

When executed correctly, this command increases the spacing between Marines to a standard distance, which is wider than the normal interval, allowing for the proper execution of movements that involve the arms, such as presenting arms or conducting various drill movements where having more space is essential for safety and effectiveness.

The other commands would not accomplish this specific goal. For instance, taking interval to the right or falling back would alter the formation but might not specifically address achieving a Double Arms Interval. Additionally, commands like "At Ease, Double Arms" do not effectively instruct the formation to adjust spacing but rather indicate a temporary relaxation of posture without adjustment to intervals.