怎么样区别加强事实和无关在suppot题目中？

一道是大全里面的题目：

10.   A year after the start an experiment to decrease crime in two high-crime subway stations by the installation of closed-circuit televisions, the experiment is being discontinued, city officials say the program has led to an increase in crime, citing the fact that following the installation, both stations showed increases in the number of crimes reported.

Which of the following, if true, most seriously weakens the claim of the city officials that the program has led to an increase in crime?

(A) The two subway stations had been chosen on the basis subway stations was higher than that of other high-crime subway stations not equipped with closed-circuit-television.

(B) The rate of increase in crimes reported for two subway stations was higher than that of other high-crime subway stations not equipped with closed-circuit television.

(C) The percentage of all crimes committed at the two subway stations that were reported rose as a result of increased instances of observations of crime on the closed-circuit televisions.

(D) The year in which the experiment was conducted was a year in which the total number of crimes reported in the city fell.（C）

1(E) Closed-circuit televisions installed in shops and stores throughout the city have proved to be useful in the prevention of shoplifting and burglaries.(无关)

为什么e是无关呢？我觉得通过在商店的例子可以看出闭路电视是有用的～当然我不否认Ｃ是正确的～

另外一个是：（og，大全都有）

9.     A conservation group in the United States is trying to change the long-standing image of bats as frightening creatures. The group contends that bats are feared and persecuted solely because they are shy animals that are active only at night.

Which of the following, if true, would cast the most serious doubt on the accuracy of the group’s contention?

(A) Bats are steadily losing natural roosting places such as caves and hollow trees and are thus turning to more developed areas for roosting.

(B) Bats are the chief consumers of nocturnal insects and thus can help make their hunting territory more pleasant for humans.

(C) Bats are regarded as frightening creatures not only in the United States but also in Europe, Africa, and South America.

(D) Raccoons and owls are shy and active only at night; yet they are not generally feared and persecuted.（D）

(E) People know more about the behavior of other greatly feared animal species, such as lions, alligators, and snakes, than they do about the behavior of bats.

为什么这个就是有关信息证明结论是不对的呢？我想了半天也没有能够说服我自己～～懂的进来告诉偶一下下吧～～谢谢咯！！！