请教885的13部分5和21提

mereiful

5.The expected rise in the price of oil could be a serious impact to industrialized nations and severely diminish the possibility to have an economy free of inflation.
(A) be a serious impact to industrialized nations and severely diminish the possibility to have
(B) seriously impact on industrialized nations and severely impede the possibility to have
(C) seriously impact on industrialized nations and severely impede the possibility of having
(D) have a serious impact on industrialized nations and severely impede the possibility to have
(E) have a serious impact on industrialized nations and severely diminish the possibility of having
答案E。请问B错在哪里呢？ a serious impact改为seriously impact 从该文上看，有没有改变原文的意思呢？ 再问一下the possibility 后面是接什么呢？
21. According to the Better Business Bureau, if you fail to advertise the highest price in a range of prices for a service or product as prominently as that of the lowest, it violates the New York Consumer Protection Law.
(A) if you fail to advertise the highest price in a range of prices for a service or product as prominently as that of the lowest, it
(B) if one fails to advertise the highest price in a range of prices for a service or product as prominently as the lowest price, it
(C) failure to advertise the highest price in a range of prices for a service or product as prominently as the lowest
(D) failure to advertise as prominently the highest price in a range of prices for a service or product as the lowest
(E) failing to advertise as prominently the highest price in a range of prices for a service or products as that of the lowest
答案C。请问这个as prominently as 在C中是修饰什么的呢？