SEO and Web Service

55) An advertiser creates a new ad group in a campaign that is set to run on all relevant sites across the Google Display Network.  If both keywords and placements are added to the ad group, they would work together to

A)  determine the target return on investment (ROI) for a given ad group

B)  impact the time of day that the ads are eligible to show

C)  restrict the ads to specific sites and show them only when the content of that sites page is relevant to the keywords

D)  impact search results and cost-per-click (CPC) on the Google Display Network