What kind of missile is designed specifically for training loaders, and is all inert?

The missile specifically designed for training loaders and is completely inert is known as the DATM. This designation stands for Dummy Air Training Missile. It is intended for use in training environments to provide realistic handling and loading conditions without the risks associated with live munitions. The inert nature of the DATM allows trainees to develop the necessary skills in a safe manner, making it an essential tool for operational readiness.

The other options represent different types of missiles that serve various purposes. For instance, the CNU-714 refers to a transport container for munitions rather than a training missile, while the AGM-88 HARM is an actual missile used for suppression of enemy air defenses, not a training device. The CATM, although also a training missile, typically includes components that may not be completely inert or could contain some functional parts, making it less suitable for basic operator training compared to the all-inert DATM. Thus, the DATM is the most appropriate choice when focusing on training loaders with a completely inert missile.