Which formation facilitates rapid movement and is effective in open terrain?

The column formation is particularly suited for facilitating rapid movement in open terrain due to its elongated shape, which allows for efficient navigation and speed. This arrangement minimizes the width occupied by the unit, enabling it to traverse narrower paths or obstacles without losing cohesion.

In open terrain, a column formation enables units to move quickly without needing to be overly spread out, maintaining a straightforward line of advance. The design of the column permits units to remain tightly packed for rapid movement, making it easier for leaders to communicate and control the operation during transit.

Moreover, because it's a single file formation, it reduces the chance of becoming bogged down in difficult terrain, allowing for a smoother flow in various environments, particularly where terrain features might restrict lateral movement. As such, the column formation is optimal for scenarios where speed is paramount, and terrain allows for such a formation's utility.