While working with your jewelry designer client, you learn that they created a line item in their Display & Video 360 web campaign that accidentally targeted mobile in-app. After removing that mobile in-app targeting at the insertion level, the campaign is still targeting mobile in-app. Why could that be?

In Display & Video 360, targeting is hierarchical. Line item targeting refines the targeting set at the insertion order level. If mobile in-app targeting was initially set at the line item level, removing it at the insertion order level will not override the more specific line item setting. To stop targeting mobile in-app, the targeting must be removed directly from the line item itself. The option "Because you can't modify targeting for mobile in-app inventory at the line item level" is incorrect because mobile in-app targeting can be set and modified at the line item level. The option "Because you can't modify insertion order targeting at the line item level" is incorrect because line items refine, not modify, insertion order targeting. The option "Because you can't modify targeting once the campaign has line items assigned" is incorrect as targeting can be modified at any time.