请教一道狒狒逻辑题。。

夏日飘雪

A rise in the percentage of all 18-year-olds who were recruited by the armed services of a small republic between 1980 and 1986 correlates with a rise in the percentage of young people who dropped out of high school in that republic. Since 18-year-olds in the republic are generally either high school graduates or high school dropouts, the correlation leads to the conclusion that the republic’s recruitment rates for 18-year-olds depend substantially on recruitment rates for high school dropouts.



Which one of the following statements, if true, most weakens the argument?



A.A large number of 18-year-old high school graduates were recruited for the republic’s armed services in 1986 than in 1980.

B.Many of the high-technology systems used by the republic’s armed services can be operated only by individuals who have completed a high school education.

C.Between 1980 and 1986 the percentage of high school graduates among 18-year-olds recruited in the republic rose sharply.

D.Personnel of the republic’s armed services are strongly encouraged to finish their high school education.

E.The proportion of recruits who had completed at least two years of college education was greater in 1986 than in 1980.

答案选C。。其他的选项都好考虑，但是我搞不懂为什么C对？
难道percentage of high school graduates among 18-year-olds recruited in the republic rose sharply，就可以weaken了？那如果缀学的percentage也rose sharply呢？而且文章也，没有说缀学的不能rose sharply啊。。

saturnor

文章的结论是recruitment rate上升和辍学的rate上升有关。。所以想削弱就应该是：大部分增加的recruitment都是来自毕业的学生。。而不是来自辍学的。。这样这两者就没有相应的关系叻
所以选c啊。。