[求助]GWD15-13

请教各位一道题

Certain genetically modified strains of maize produce a powerful natural insecticide.  The insecticide occurs throughout the plant, including its pollen.  Maize pollen is dispersed by the wind and frequently blows onto milkweed plants that grow near maize fields.  Caterpillars of monarch butterflies feed exclusively on milkweed leaves.  When these caterpillars are fed milkweed leaves dusted with pollen from modified maize plants, they die.  Therefore, by using genetically modified maize, farmers put monarch butterflies at risk.

Which of the following would it be most useful to determine in order to evaluate the argument?

A Whether the natural insecticide is as effective against maize-eating insects as commercial insecticides typically used on maize are
B Whether the pollen of genetically modified maize contains as much insecticide as other parts of these plants
C Whether monarch butterfly caterpillars are actively feeding during the part of the growing season when maize is releasing pollen
D Whether insects that feed on genetically modified maize plants are likely to be killed by insecticide from the plant’s pollen
E Whether any maize-eating insects compete with monarch caterpillars for the leaves of milkweed plants growing near maize fields

ANWSER:c,我看不出C和E有什么区别，老帖也没有很好的说明，希望各位高手帮忙

我是新手，C和E完全不一样啊：

C Whether monarch butterfly caterpillars are actively feeding during the part of the growing season when maize is releasing pollen

意思是：玉米花粉产生的季节，君主蝴蝶的幼虫是否很活跃地吃东西。如果玉米花粉产生的时候，幼虫不吃东西，就不会伤害到它们。

E Whether any maize-eating insects compete with monarch caterpillars for the leaves of milkweed plants growing near maize fields

意思是：是不是有其他吃玉米的昆虫跟君主蝴蝶幼虫抢Milkweed的叶子吃。也就是说玉米地会吸引很多吃玉米的昆虫过来，这些昆虫会把旁边的milkweed的叶子也抢吃了。这个比较牵强。

我说说我的看法

结论为若农夫种植genetically modified maize会害死monarch butterflies

而c表示是否monarch butterflies在maize释放花粉期间是主要actively feeding

->若是,则结论成立;

若否,则结论不成立

E是否有其它昆虫与monarch caterpillars竞争

->无关,因为到底会不会吃才是重点,从E选推不出其它昆虫与monarch caterpillars在争夺”吃”