Although tales of wonder and the fantastic are integral to all world literatures, only recently has the fantasy genre had a commercial resurgence in North America. During the last 20 years, sales of fantasy-fiction books written for adults have gone from 1 to 10 percent of total adult-fiction sales. At the same time, the number of favorable reviews of fantasy books has increased markedly. Some booksellers say that the increased sales of fantasy books written for adults can be traced to the increased favorable attention given the genre by book reviewers. Which one of the following, if true, undermines the booksellers' explanation of the growth in sales of fantasy-fiction books for adults? ['Although the increase in the percentage of fantasy books sold has been substantial, publishers estimate that sales could increase even further.', 'Publishers often select a manuscript on the basis of whether they think that the published book will receive favorable reviews by book reviewers.', 'Few readers of fantasy fiction read book reviews, and even fewer select books to purchase on the basis of those reviews.', 'Many of the book reviews of new fantasy- fiction novels also mention great fantasy novels of the past.']