What is the role of a Prearranged Barrier of Fire?

The role of a Prearranged Barrier of Fire is primarily to stop enemy movement across defensive lines. This tactic involves the strategic placement of machine guns and other fire support in order to create a formidable barrier that disrupts and inhibits the enemy's advance. By designating specific areas where fire will be directed, commanders can predict and control the battlefield, effectively limiting the enemy's capabilities to maneuver and attack.

Creating such a barrier serves to enhance the defensive posture of friendly forces by concentrating firepower on key routes or zones that the enemy is expected to exploit. This method not only increases the effectiveness of firepower but also minimizes the risk of friendly fire incidents, as attackers can be engaged before they breach the defensive line.

In contrast, other roles suggested by the other choices may not align with the primary objective of the Prearranged Barrier of Fire. Deterring enemy aircraft, providing safe routes for allied forces, and signaling troop movements are important aspects of military operations; however, they do not reflect the main function of creating a direct and defensive measure against enemy ground forces. The focus of the barrier is fundamentally about controlling and halting enemy ground movement, which strengthens the defensive capabilities of friendly units in combat situations.