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 pesticide, 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 the 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 varieties in the past.
spoiler:

Explanation:

In order to make a choice to answer the question: Which of the following would be most useful to know in evaluating the argument above, we must first understand what it is that the excerpt is giving us. So, first, we learn that there are seeds that are being engineered that are highly resistant to insect damage, but, there is a downside to this; they are expensive. However, given the benefits in the long term for farmers, it is forseen that these seeds will become more used than regular seeds used today, because they will reduce the costs in other areas.

Seeing the conclusion of the excerpt, which says that most likely the newly engineered seeds will be used more frequently than the others, but also learning before that that the cost per seed is higher than regular seeds, you would of course wish to evaluate the validity of such information by placing yourself in the shoes of these farmers. They would be interested in the cost-benefit balance of this to actually decide whether they would go for one type of seed, or the other. Looking at that cost-benefit scale, then, you would most likely ask:

D) Whether the seeds genetically engineered to produce insect-resistant crops (would) generate significantly lower per acre crop yields that do currently used seeds.

This is because you, as a farmer, would like to know if the investement will pay off in the long run, or not.

c is the correct answer!