Final answer:
BNA portfolios are grouped by area of common topic into sub-folders, collections, journals, and guides. All these are applicable.
Step-by-step explanation:
BNA portfolios are grouped by area of common topic into:
- sub-folders
- collections
- journals
- guides
A BNA portfolio is a collection of writing contained within a single binder or folder. It may be organized chronologically, thematically, or according to quality.
The grouping of portfolios by area of common topic could be done using sub-folders, where each sub-folder pertains to a specific topic or theme. These sub-folders allow for efficient organization and easy access to the relevant pieces of writing.