Which statement best describes active vs inactive relationships in a data model?

• A. Only one active relationship can exist between two tables, and inactive relationships cannot be used unless activated in a measure.
• B. There can be multiple active relationships between two tables.
• C. Inactive relationships are always ignored in calculations.
• D. Active relationships can always be changed dynamically without DAX functions.

Answer: (A)

Active relationships determine the default path through which filters flow between two tables. You can create several relationships, but only one can be active at any time; that active relationship is the one used by default in calculations. Inactive relationships exist for flexibility—they won’t affect normal calculations unless you explicitly activate them in a measure, typically using DAX like CALCULATE with USERELATIONSHIP to switch to that relationship for that calculation. This is why the statement describes that only one active relationship can exist and that inactive ones can be used only when activated in a measure. The other options fail because you cannot have multiple active relationships between the same two tables, inactive relationships aren’t automatically used in calculations, and switching the active relationship on the fly requires explicit DAX logic.