A)  Advertisers can identify the Internet Protocol (IP) address of users who are searching for products
B)  Ads can include up to 50 characters for the first three lines of ad text
C)  Ads are displayed to users who are searching for a particular product of service
D)  Advertisers can pay to place their websites in the natural search results

Right answer is

C)  Ads are displayed to users who are searching for a particular product of service