不明白，杀虫剂，求解

crack25

Caterpillars of all species produce an identical hormone called "juvenile hormone" that maintains feeding behavior. Only when a caterpillar has grown to the right size for pupation to take place does a special enzyme halt the production of juvenile hormone. This enzyme can be synthesized and will, on being ingested by immature caterpillars, kill them by stopping them from feeding.

Which of the following, if true, most strongly supports the view that it would not be advisable to try to eradicate agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme mentioned above?

(A) Most species of caterpillar are subject to some natural predation.

(B) Many agricultural pests do not go through a caterpillar stage.

(C) Many agriculturally beneficial insects go through a caterpillar stage.

(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary.C

(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet.

突然不明白了，为什么B不对？取反削弱正好符合了原文的荷尔蒙抑制那个。。。而为什么大家不觉得C 益虫是文章新引入的呢？

ffen

同不明白。求教~!

kikisunflower

B才是无关选项。

原argument讨论的是，这个方法是否适用于经历毛虫阶段的虫子。

B说很多虫子都不经历毛虫阶段，和原argument无关。因为即使有很多虫子都不经历毛虫阶段，也并不妨碍这个方法对少数害虫适用。

zhanglicser

本题的题目明确说明，是eradicate agricultural pests that go through a caterpillar stage，所以B选项是无关的