LAST 4-1-21政治题一道看不懂

21. Whenever a major political scandal erupts before an election and voters blame the scandal on all parties about equally, virtually all incumbents, from whatever party, seeking reelection are returned to office. However, when voters blame such a scandal on only one party, incumbents from that party are likely to be defeated by challengers from other parties. The proportion of incumbents who seek reelection is high and remarkably constant from election to election.
If the voters’ reactions are guided by a principle, which one of the following principles would best account for the contrast in reactions described above?
(A) Whenever one incumbent is responsible for one major political scandal and another incumbent is responsible for another, the consequences for the two incumbents should be the same.
(B) When a major political scandal is blamed on incumbents from all parties, that judgment is more accurate than any judgment that incumbents from only on party are to blame.
(C) Incumbents who are rightly blamed for a major political scandal should not seek reelection, but if they do, they should not be returned to office.
(D) Major political scandals can practically always be blamed on incumbents, but whether those incumbents should be voted out of office depends on who their challengers are.
(E) When major political scandals are less the responsibility of individual incumbents than of the parties to which they belong, whatever party was responsible must be penalized when possible.

答案是E,我完全不明白，请大虾执教

多谢大虾执教：）

But if the party which is involved into scandles will be penalized, then, why "The proportion of incumbents who seek reelection is high and remarkably constant from election to election" ？

Looking forward reply. Thank you

这个是题干给你的信息，你承认就行啦！至于为什么嘛，呵呵，偶也不知道……