请多帮忙！谢谢。
Although it claims to delve into political issues,
television can be superficial such as when each of
the three major networks broadcast exactly the
same statement from a political candidate.
(A) superficial such as when each of the three
major networks
(B) superficial, as can sometimes occur if all of the
three major networks
(C) superficial if the three major networks all
(D) superficial whenever each of the three major
networks
(E) superficial, as when the three major networks
each
My answer: B,correct answer: E.
"broadcast"是复数形式，为什么前面要用"each"?ffice ffice" /> | 
