What must be attached to mandatory, essential, and highly desirable priorities?

The correct choice emphasizes the significance of the Casualty Report (CASREP) in the context of maintenance and material management within the Navy. A CASREP is a formal communication that conveys information about equipment casualties that impair mission capability. When equipment is classified under mandatory, essential, or highly desirable priorities, a CASREP must be attached because these priorities signify varying levels of urgency in addressing equipment failures or anomalies.

To ensure that necessary resources are allocated to rectify critical equipment issues, the CASREP provides specific details about the problem, the impact on operations, and the recommended corrective actions. This structured communication helps maintenance and logistics support teams prioritize their efforts effectively, ensuring that critical systems are restored to operational status swiftly.

The other options, while relevant to maintenance protocols, do not carry the same level of urgency or specific requirement for reporting and prioritization as the CASREP does. Task Orders and Work Approvals typically focus on authorizing and scheduling maintenance work without explicitly linking to the urgency of operational priorities. Equipment Logs serve as records of maintenance activities and operational history but do not serve the same purpose in communicating urgent status for mission capability as a CASREP does.