What is the nomenclature for ILLUM?

The correct nomenclature for ILLUM is M314. This designation refers specifically to the illuminating projectile used in artillery, providing military forces with the capability to light up an area for target identification or adjustment of fire at night or during reduced visibility conditions. The M314 round is designed to illuminate a designated target area, assisting troops in understanding their operational environment during nighttime maneuvers.

The other choices represent different types of ammunition and projectiles that serve various purposes but do not pertain to illuminating projectiles. Each has its specific roles within artillery and munitions, distinct from what the M314 provides in terms of illumination capabilities.