(A) Return on ad spend and other cost based metrics are available within your Amazon Attribution console.
(B) Register for Amazon Attribution cost reports.
(C) Calculate cost efficiency metrics, such as Return on ad spend, Cost per purchase, and Cost per DPV, by exporting your Amazon Attribution reporting and adding in your media cost offline.
(D) It is not possible to calculate Return on ad spend and other cost based metrics.
This question is a part of the Amazon Attribution beta (Vendor) Quiz.