How should a campaign business practitioner verify the union activity inputs are based on?

A workflow log indicates an incompatible document type error on a union activity.

How should a campaign business practitioner verify the union activity inputs are based on?
A . The union activity’s inputs are based on the same target mapping
B . The union activity’s inputs are based on the same filtering dimension
C . The union activity’s inputs are based on the same targeting dimension
D . The union activity’s inputs are based on the same global dictionary

Answer: C