Final answer:
The question asks for the specific volume of WMP that guides WRM prepositioning at overseas bases for wartime. Accurate answering requires access to military or government contingency planning documents, which is not provided.
Step-by-step explanation:
The student is inquiring about a specific volume from the War Mobilization Planning (WMP) directives that deal with the prepositioning of War Reserve Materiel (WRM) at overseas locations. While the exact volume number or directive is not provided within the given information, it's assumed to be a part of logistical and contingency planning documents managed by the military or related government entities. It's important to note that the provided information about WCCA Assembly Center, WRA Relocation Center, and ballast water discharge does not directly relate to WMP volumes or WRM prepositioning.
For an accurate response, further research or access to a database of WMP volumes would be necessary to find out which WMP volume directs that WRM will be prepositioned at overseas locations for wartime at the base of intended use when possible.