betterscore wrote:
Which of the following most logically completes the argument below?
Using broad-spectrum weed killers on weeds that are competing with crops for sunlight, water, and nutrients presents a difficulty: how to keep the crop from being killed along with the weeds. For at least some food crops, specially treated seed that produces plants resistant to weed killers is under development. This resistance wears off as the plants mature. Therefore, the special seed treatment will be especially useful for plants that _____________ .
(A) produce their crop over an extended period of time, as summer squash does
(B) produce large seeds that are easy to treat individually, as corn and beans do
(C) provide, as they approach maturity, shade dense enough to keep weeds from growing
(D) are typically grown in large tracts devoted to a single crop
(E) are cultivated specifically for the seed they produce rather than for their leaves or roots
Source : OG2017, CR609, P529
Weed Killers Step 1: Identify the QuestionThe question stem appears before the argument and the argument contains a blank line at the end, signaling a Fill in the Blank structure. These types of arguments are most often Strengthen questions but can also be Inference or Find the Assumption questions.
In this case, the structure Therefore, the treatment will be useful for plants that ______ indicates that this is an
Inference question. The argument is asking you to complete the conclusion of the argument.
Step 2: Deconstruct the ArgumentBSWK diff: kill weeds, not crop?
Some foods: seeds à resistant to WK
BUT wears off over time
SO useful for plants that…?
You’re a farmer. Based on what you know so far, when would you want to use this special treatment? Perhaps on plants that mature really quickly, so that they’re ready to harvest before the resistance wears off?
(Note: that possibility does not turn out to be the focus of the correct answer, but if you do brainstorm something, note it. Sometimes, you’ll realize that you’ve just anticipated the correct answer!)
Step 3: Pause and State the GoalInference questions are asking you to find a conclusion that must be true given the information in the argument. Think of yourself as a scientist: what can you scientifically conclude from the given information? (Don’t follow “real-world” principles, where it would be enough to say something is likely to be true. That’s not good enough on the GMAT.)
Step 4: Work from Wrong to Right(A) This choice is the opposite of what you want, according to the argument. The resistance wears off over time, so a crop that takes a long time to mature is not a good candidate for this special treatment.
(B) The argument doesn’t indicate that the treatment is better if you can treat the seeds individually vs. in a big pile of seeds. Both methods might be equally effective (or it might even be better to be able to treat a big pile of seeds at once!).
(C)
CORRECT. The argument mentions one major drawback to the special treatment: it wears off as the crops mature. If certain crops naturally deter weeds by providing dense shade as they mature, then these crops have another method to counteract weeds just at the point that the special resistance is wearing off. These types of crops combat the one drawback to the special treatment.
(D) The argument does not indicate whether it is better to have crops that are grown in relative isolation.
(E) The argument does not indicate that the treatment works better depending on whether the harvesting of the crop is focused on seeds (for instance, sunflower seeds), leaves (for instance, lettuce), or roots (for instance, beets or carrots).
How is d incorrect? D says typically grown in large tracts. If the crops are grown in large tracts it would be easier to use weed killers on them as it wouldn’t harm the other plants which would otherwise be growing with them.