Official Explanation
The scenario presents us with a paradox. Both the plan and the further information seem to suggest reasons that the barley crop would have taken off, giving tremendous economic benefit to the barley growers, but the "results" section tells us this didn't happen. We need some further piece of information that would explain why, despite all the apparently favorable conditions, the barley didn't grow.
(C) is the credited answer. If the material added to the barley fields included an enzyme that multiplied the growth of a bacteria that fed on the barley, that would explain how something involved in the plan itself had the counteractive effect of inhibiting the success of the barley plants, which in turn would explain why the barley didn't grow and why the barley growers were no better off as a result of this plan.
(A) if anything would make us expect that the plan would have been a success, so it certainly doesn't explain why it wasn't successful.
(B) is irrelevant: the fertilizer & enzyme mix is sent in autumn to be used in the spring. That's a delay of 4-5 months, so the extra 4-5 days the truck takes will make no difference.
(D) underscores the nature of the problem the NFA was trying to solve --- yes, it was a big problem. Unfortunately, this doesn't at all explain why the plan didn't work. The mix sent to the farmers was free, so there were no additional expenses for the farmers associated with this plan. Therefore, the economic standing of the farmers has no bearing on whether the barley would grow.
(E) is an argument by analogy. Fourteen years ago, the NFA had a plan that didn't work, so that's why this plan didn't work. This is a very weak attempt at explanation. There is absolutely no guarantee that whatever caused the failure of the plan 14 years ago had any influence on the implementation of the current plan.
Frequently Asked QuestionsQ: I chose answer choice D, and I don't understand why C is the best option. Can you explain a bit more?A: We are told that this special mix "had been stunningly
successful in multiplying the yield of barley in laboratory
conditions." Therefore, it is reasonable for us to assume that the mix
should increase the yield of barley in the field, unless we are
told other information that would contradict it. It would therefore be
unreasonable for us to assume that the special mix would not increase
the yield at all, again unless we are told some other piece of information.
The reason C is the best answer choice here is somewhat subtle, but the reason D is incorrect is pretty straightforward, so let's start with D and then return to C.
So in this question, we're being asked which answer choice best
explains the paradox we're given. The paradox is that, even though the
barley farmers all received and used the fertilizer given to them by the
NFA, and even though that fertilizer was very successful in multiplying
barley yields in the lab, for some reason "most barley growers reported little change in their economic status over this two year period."
In other words, we are being asked to select the answer choice that best explains why the barley growers' economic situation didn't improve. So, that's the criteria we need to use when evaluating each of the answer choices we're given.
So let's look at D:
"This program was implemented at a time when more than
half of barley growers nationwide were reported barely breaking even in their yearly expenses."
This might sound like it a possible reason because it might seem like the fertilizer could have played some role in causing this economic hardship among the barley growers.
However, the "Results" have already told us that there was little change in the farmers' economic status during this time period:
"Most barley growers reported little change in their economic status over this two year period."
And because the economic status did not significantly change
during this period, we can therefore confidently rule out D.
So now let's look at why C is correct. Here's C:
"Some of the enzymes in the special mix multiply the growth of a bacteria that feeds on the young barley plants."
Here we are given some new information to work with.
And the new information we're given is that some enzymes in the
fertilizer cause a bacteria to multiply that likes to eat barley plants. This could certainly be the reason that explains the paradox.
In other words, we are told in the passage only that the fertilizer is successful in the lab in multiplying the barley yield. But we are NOT told whether the fertilizer also multiplies something else. But in choice C, we ARE told that the fertilizer multiples something else. And that something else is a bacteria that would directly counteract the fertilizer's benefits, therefore producing a more neutral overall (or net) effect on the barley yield for the farmers.
Q: If the answer is C, then how-come the lab testing gave stunning result? Shouldn't this show up on the lab test?A: The key here is thinking about the difference between laboratory conditions and real world conditions. In a laboratory, everything is likely clean, sterile, and controlled. Therefore, there is a good chance that a bacteria that is common on actual farms is not in the laboratory. Therefore, there is actually a good chance that results will differ between a laboratory and the real world! Just because a certain outcome occurs in one environment, does not mean that the same outcome will occur in all environments: we cannot guarantee the same growth conditions.