大家说这题选什么应该？答案是Ｄ　是不是有错

Plant scientists have been able to genetically engineer vegetable seeds

to produce crops that are highly resistant to insect damage. Although

these seeds currently cost more than conventional seeds, their cost is

likely to decline. Moreover, farmers planting them can use far less pes-

ticide, and most consumers prefer vegetables grown with less pesticide,

Therefore, for crops for which these seeds can be developed, their use

is likely to become to norm.

Which of the following would be most useful to know in evaluating the

argument above?

A. Whether plant scientists have developed insect-resistant seeds

for every crop that is currently grown commercially

B. Whether farmers typically use agricultural pesticides in larger

amounts than is necessary to prevent crop damage

C. whether plants grown from the new genetically engineered seeds

can be kept completely free of insect damage.

D. Whether seeds genetically engineered to produce insect-resistant

crops generate significantly lower per acre crop yields than do

currently used seeds.

E. Whether most varieties of crops currently grown commercially have

greater natural resistance to insect damage than did similar vari-

eties in the past.