What are the three fighting positions used in a defense?

The correct choice identifies the three essential fighting positions used in a defense: Primary, Alternate, and Supplementary.

In defensive operations, the primary position is the main point where effective defense is established to engage the enemy. The alternate position serves as a backup, allowing forces to shift to a different location if circumstances change or if the primary position becomes untenable. The supplementary position is used to further enhance the defensive capabilities, acting as an additional layer of defense or providing support to the primary and alternate positions. This structure enhances flexibility and ensures that defenders can adapt to an evolving battlefield scenario, maintaining the effectiveness of the defense despite changes in enemy tactics or pressure.

Understanding these positions is crucial for effective defense, as it allows commanders and troops to plan and execute their strategies with a clear understanding of their roles and the necessary contingencies.