(A) The All Traffic > Source/Medium report does not include view-through sessions
(B) The All Traffic > Source/Medium report uses the Google Analytics attribution model (GA Model) while the Acquisition > Google Marketing Platform > Display & Video 360 reports use the Campaign Manager attribution model (CM Model)
(C) The All Traffic reports use the date range set in Google Analytics while the Acquisition > Google Marketing Platform > Display & Video 360 reports report sessions during the lookback window
(D) The All Traffic > Source/Medium report may be sampled while the Acquisition > Google Marketing Platform > Display & Video 360 reports are always unsampled
The Acquisition > Google Marketing Platform > Display & Video 360 Reports show View-through sessions which are sessions in which the visitor saw an ad impression from a Display & Video 360 campaign and then they clicked on the ad and visited your website. The CM model attributes the session to the Campaign Manager. The All Traffic > Source/Medium Report follows Last Non-Direct Click which does not include View through Sessions.
In the CM Model, the attribution of Analytics sessions to Campaign Manager campaigns is done by considering Campaign Manager only and ignoring all other channels that drive traffic to your site. The GA Attribution model follows the Last Non-Direct Click Model where direct visits from returning visitors are ignored and the attribution of Analytics sessions is given to the previous channel. Since the GA model ignores direct sessions from returning users, the number of sessions recorded in the GA model is always less than the CM Model.
This question is a part of the Assessment 3 exam of Getting Started with Google Analytics 360. You can find all the answers to this exam in our Getting Started with Google Analytics 360 Assessment Answers page.