请教一道gwd题目

plmijb1

Scientists have made genetic modifications to cotton to increase its resistance to insect pests. According to farmers' reports, the amount of insecticides needed per acre to control pests was only slightly lower for those who tried the modified seed than for those who did not. Therefore, since the modified seed costs more than ordinary seed without producing tields of higher market value, switching to the modified seed would be unlikely to benefit most cotton farmers economically.
Which of the following would it be the most useful to know in order to evaluate the argument?
D whether the farmers who tried the modified seed planted as many acres of cotton, on average, as the farmers using the ordinary seed did.
E whether most of the farmers who tried the modified seed did so because because they had preciously had to use exceptionally large quantities of insecticides.
答案是D，为什么不是E呢， 个人认为D与题目没什么关系

gwang5

同问。也觉得E靠谱啊。