What is reviewed to determine the inclusive series number when files expand?

The inclusive series number is determined by referencing the file plan. The file plan outlines how records are organized, categorized, and described within an organization. It helps establish the parameters for the lifecycle of the records, including any expansions in files. When files expand, reviewing the file plan ensures that new records are consistently categorized and aligned with existing ones. This allows for accurate identification and management of records over time, making it critical for maintaining an organized records management system.

The other options, while relevant in their own contexts, do not specifically address the need for categorizing expanded files in relation to their inclusive series numbers.