[求助]请教一道题

 Because incumbent members of Congress are given a great deal of attention by the news media and because they enjoy such perquisites as free mail privileges and generous travel allowances, incumbents enjoy an overwhelming advantage over their challengers in elections for the United States Congress.

Which of the following, if true, best supports the claim above?

(A) In the last congressional elections, incumbents met with a larger number of lobbyists than did

challengers.

(B) In the last congressional elections, 98 percent of the incumbents in the House of Representatives

who were seeking reelection won.

(C) Incumbent members of Congress are frequently critical of the amount of attention given to them

by the news media.

(D) The support that political station action committees provide to challengers for congressional

seats often compensates for the perquisites enjoyed by incumbent members of Congress.

(E) Of all incumbent senators surveyed before the last congressional elections, 78 percent said that

their challengers did not pose a serious threat to their chances for reelection.

我看到的答案是e,可是自己觉得是d,希望有高手能够解释一下，谢谢大家

I chose E for E (their challengers did not pose a serious threat to their chances for reelection) results from "incumbents enjoy an overwhelming advantage over their chanllengers". Because of the advangages they enjoy, incumbents don't face serious chanllanges at all.