For advertisers bidding on maximum CPC basis, Quality Score on the Display Network is evaluated on the:
A) Quality Score of all campaigns and regional targeting settings
B) Quality Score of keywords across all campaigns and all ad groups
C) click-through rate (CTR) of the ad and relevance of the ad text and keywords to the publisher’s site
D) clickthrough rate (CTR) of all keywords across the account and the relevance of the ad text and keywords to the advertiser’s landing page