Sub-population A of 100 records and B of 200 records are combined in a campaign workflow with a Union activity. The resulting population C contains 200 records. What should the Practitioner conclude?

The Union activity in an Adobe Campaign workflow combines the results of inbound activities and removes duplicates. The size of the resulting population (C) can be calculated using the set theory formula: |C| = |A| + |B| - |A ∩ B|. Given the values: |A| = 100 |B| = 200 |C| = 200 The calculation is: 200 = 100 + 200 - |A ∩ B|. Solving for the intersection, |A ∩ B| = 300 - 200 = 100. Since the size of the intersection (100) is equal to the total size of population A (100), it logically follows that every record in population A is also contained within population B.

A. Records in A have been excluded from C. This is incorrect. A Union activity includes all unique records from all inbound sets. The records from A are part of the final population C.
C. All of the records in B are also in A. This is incorrect. If all records in B were also in A, the union of A and B would be A itself, resulting in a population of 100, not 200.
D. A and B are mutually exclusive. This is incorrect. If the populations were mutually exclusive (no common records), the union would be the sum of both, resulting in 300 records (100 + 200).

1. Adobe Campaign Classic v7 Documentation, Targeting activities, Union: "The result of a union contains all the elements from the inbound transitions, without duplicates." This confirms the deduplication behavior which is central to the question's logic.

Source: Adobe Experience League. (n.d.). Union. Adobe Campaign Classic v7 Documentation. Retrieved from https://experienceleague.adobe.com/docs/campaign-classic/using/getting-started-with-workflows/targeting-activities/union.html (Refer to the "Description" section).

2. Adobe Campaign Standard Documentation, Workflows, Union: "The Union activity combines all inbound populations. If a recipient is present in multiple inbound populations, they will only be kept once in the output population." This statement directly supports the principle that the final count of 200 implies a complete overlap of the smaller population (A) within the larger one (B).

Source: Adobe Experience League. (n.d.). Union. Adobe Campaign Standard Documentation. Retrieved from https://experienceleague.adobe.com/docs/campaign-standard/using/managing-processes-and-data/targeting-activities/union.html (Refer to the "Using the Union activity" section).