49. What does the author most likely mean by the phrase “bombard users with ads that appear tailor-made for them”? (A) Google exhausts their users by making them fill out a lot of ad surveys. (B) Google helps their users to promote themselves by posting information to the public. (C) Google tricks users to buy products they do not need by giving them special discounts. (D) Google makes users believe that they are given individualized services of product information.