Which of the following best describes deployable strength?

Deployable strength refers specifically to the number of personnel who are ready and available for immediate deployment missions. This includes individuals who are not currently engaged in other commitments that would prevent them from being promptly sent to support a military operation. The focus on readiness and availability makes this choice accurate, as deployable strength is fundamentally about the capability to quickly mobilize resources and personnel when needed.

In contrast, the other options either describe personnel in specific statuses that may not relate to immediate deployment or focus on different aspects of military organization. For instance, personnel authorized by MTOE (Table of Organization and Equipment) may include individuals who are not necessarily prepared for immediate deployment, as they might be in various stages of assignment or responsibility. Personnel currently in training exercises are not deployable since their focus is on training rather than being mission-ready. Lastly, those attached to supporting units may serve vital roles, but they might not be classified as deployable if their immediate tasks do not include waiting for assignment to missions.