Advertising by mail has become much less effective, with fewer consumers responding. Because consumers are increasingly overwhelmed by the sheer amount of junk mail they receive, most discard almost all offers without considering them. Thus, an effective way for corporations to improve response rates would be to more carefully target the individuals to whom they mail advertising, thereby cutting down on the amount of junk mail each consumer receives. Which of the following, if true, would most support this recommendation? ['Response rates to carefully targeted advertisements by mail are considerably higher, on average, than response rates to most other forms of advertising.', 'Improvements in the quality of the advertising materials used in mail that is carefully targeted to individuals can improve the response rate for such mail.', 'There are cost-effective means by which corporations that currently advertise by mail could improve response rates.', 'Many successful corporations are already carefully targeting the individuals to whom they mail advertising.']