What command is given to form a platoon at close interval?

The command to form a platoon at close interval is "At Close Interval, Fall In." This command specifically instructs the personnel to line up in close formation, which means they should stand closer together than they would in regular formation.

Using this command emphasizes the need for compactness in the formation, which may be necessary for situations where space is limited or where a closer formation is tactically advantageous. It ensures that the platoon remains organized and ready for immediate actions or movements as a unified group.

Other commands listed do not convey the specific requirement for close interval; they either imply a more relaxed posture, such as "At Ease, Fall In," or simply standard formation commands without the close interval specification. Therefore, the correct choice provides the necessary directive for the specific context of establishing a close interval formation effectively.