When is an Attack by Fire typically utilized?

An Attack by Fire is typically utilized when the goal is to inflict damage on superior forces while minimizing direct engagement. This tactic is especially effective against an enemy that possesses a numerical or tactical advantage. The use of indirect fire or aerial capabilities allows a unit to engage the enemy from a safer distance, reducing the risk of casualties among friendly forces. In situations where direct confrontation might lead to heavy losses, executing an Attack by Fire can disrupt enemy operations and create conditions for more favorable engagement or maneuvering.

The other options do not align well with the primary purpose of an Attack by Fire. For instance, sustaining heavy casualties typically calls for a more defensive posture or maneuvering to avoid engagement rather than focusing purely on inflicting damage. Closing with the enemy often involves assault tactics that put forces at greater risk, contradicting the idea of reducing direct engagement. A full frontal assault asserts an aggressive approach that places units at the forefront of enemy fire rather than utilizing indirect methods to inflict damage. Hence, option C clearly aligns with the operational concept of engaging superior forces through indirect means rather than direct confrontation.