To extend a dimension in a custom subject area by adding new attributes at the source, what basic steps are required in User Extensions of Semantic Model Extensions?

• A. Delete the subject area and recreate with the new attributes.
• B. Create a sandbox and edit an existing logical star, then modify the subject area to expose the new elements.
• C. Directly modify the production model and refresh.
• D. Create a new subject area and copy elements from the old one.

Answer: (B)

When you want to extend a dimension by adding new attributes at the source, do it in a controlled, isolated way and make the new elements available to users only after validation. Start in a sandbox and bring in the new attributes by editing the existing logical star to include them from the source. Once those attributes are added and validated, modify the subject area to expose the new elements so analysts can use them in reports and analyses. This approach keeps production untouched, preserves existing mappings, and avoids duplicating subject areas or re-creating structures.