The most efficient Advertising campaign has the lowest ACOS %. ACOS means the total % of sales you’re spending on Ads. So, if a campaign has low % of ACOS it means you are spending less % of your revenue on Ads. Among the options, the lowest % of ACOS is 12% so, the most efficient advertising campaign is the one with 12% ACOS.
This question is a part of the Amazon Sponsored Ads Foundations Certification Assessment. You can find answers to all the questions asked in this exam in our Amazon Sponsored Ads Foundations Certification Assessment Answers page.