What actions are taken during property disposal:

The correct answer focuses on the essential process of properly eliminating unneeded or outdated inventory. In the context of property disposal, this is a critical action because it ensures that items that are no longer valuable to the military's operational capacity are removed from inventory records, preventing unnecessary costs associated with storage and maintenance. Proper disposal processes also adhere to regulations and guidelines, which are important for maintaining accountability and compliance.

Efficiently managing inventory not only reduces clutter and frees up resources but also helps to maintain an up-to-date understanding of current assets. This is vital for strategic planning and resource allocation. The disposal of outdated and unneeded items supports overall operational readiness and serves to streamline logistics.

Other options like building new storage facilities or creating a new inventory management system do not directly pertain to the act of disposing of existing property, while capitalizing on outdated items for maintenance training may not facilitate effective disposal. Therefore, focusing on properly eliminating unneeded or outdated inventory is the correct and most relevant action during the property disposal process.