Which of the following indicates the direct space between individuals in a formation?

The term that indicates the direct space between individuals in a formation is "interval." In military formations, the concept of interval refers specifically to the distance between individuals or elements, ensuring that they maintain an appropriate separation for effective movement, communication, and overall unit cohesion. This is crucial in maintaining operational effectiveness and safety during maneuvers.

Distance is a broader term that can refer to various types of separations, while placement generally relates to the positioning of units rather than the space between them. Spacing may be used in different contexts to describe the arrangement of units or individuals but does not specifically denote the direct space between individuals. Therefore, "interval" is the precise term that accurately captures the relationship being questioned.