Which definition best matches the term "commingle"?

The term "commingle" refers to the action of mixing or blending different items together. In this context, maintaining items in a single location highlights the idea of those items being kept together or combined rather than separated. The definition aligns well with the concept of commingling, where items are not kept apart but rather integrated.

The other definitions do not capture the essence of commingling. Separating and categorizing items would imply distinguishing between them, while dividing into subgroups refers to organizing items into distinct categories. Unassembling completely indicates taking apart or disassembling, which is the opposite of the idea of combining or keeping items together. Thus, the best match for "commingle" is the concept of maintaining in a single location.