Surveys in Domorica indicate that only 10 percent of Domoricans in their
twenties read a newspaper regularly, while more than half of all Domoricans
over thirty read a newspaper regularly. Although Domoricans in their twenties
constitute a large proportion of the population, newspaper publishers
nonetheless predict that ten years from now, the percentage of Domoricans who
regularly read a newspaper will probably be no lower than it is today.
Which of the following, if true, provides the strongest grounds for the
newspaper publishers' prediction?
A.The number of Domoricans in their twenties is less than the number of
Domoricans over thirty.
B.The number of newspapers in Domorica has been gradually increasing over
the past several decades.
C.The proportion of Domoricans in their twenties who regularly read a
newspaper has always been low.
D.The surveys defined a regular reader of a newspaper as someone who reads a
newspaper more than twice a week.
E.The proportion of Domoricans who regularly read a newspaper was higher 20
years ago than it is today.
這題OA是C，但想不通為什麼"D國二十代閱報比例一直以來都很低"可以支持Support十年
後D國閱報的人口不會比現在還低的論點？
再板友麻煩幫忙解答，謝謝

首先文內已經前提過了30歲的人是閱讀報紙的最大群眾20歲的是少眾閱讀報紙但是人數最多，過了10年20歲變30歲就會變閱讀的大眾，自然而然報紙就會上升答案要有一個設定就是這些20歲的人不會改變習慣，如果改變，那10年後的結果很不一定試著去想這是一個SOP 20歲人數多但讀的人數最少30歲讀的人數最多，所以我們要保持這個連結不能有額外可能性補充:這是一個小轉大的概念 要保證10年後不會比現在少讀報紙，假設如果20歲的人有增加閱讀數量，那十年後閱讀報紙的總量不一定會增加，因為那些增加量已經被統計過在過去的總量裡頭，所以十年後實際成長的幅度就不會提高，因此就可能不一定比現在高希望有幫助到你，我也還在學習，若有錯誤請指教

謝謝樓上解答