Early in the twentieth century, Lake Konfa became very polluted. Recen

Early in the twentieth century, Lake Konfa became very polluted. Recently fish populations have recovered as release of industrial pollutants has declined and the lake' waters have become cleaner. Fears are now being voiced that the planned construction of an oil pipeline across the lake’s bottom might revive pollution and cause the fish population to decline again. However, a technology for preventing leaks is being installed. Therefore, provided this technology is effective, those fears are groundless.

Which of the following,if true, seriously weakens the argument?

Conclusion : those fears are groundless
Premise 1: a technology for preventing leaks is being installed
Premise 2 : provided this technology is effective

A) The Pipeline's construction will disturb sediments at the bottom of the lake, dispensing into the water toxic pollutants that have settled there.
This option creates doubts that pollution will occur not because of the leakage but because of pipeline construction -> So it follows the premise 2 and finds faults with other things during the construction of the pipeline
This weakener option is attacking the assumption of the argument

B) Changes in the land use and drainage patterns around the lake mean that the lake's waters are increasingly likely to be affected by agricultural runoff.
This option talks about general land use and drainage pattern which is always present. This option has nothing to do with construction of pipelines.
Hence doesn't weaken the argument in scope

C) The leak-preventing technology has been in use for several years without any pipeline in which it is installed developing serious leaks.
This is a neutral arguments and provides a general information about the leakage and it is not concerned about the argument

D) A major leak of oil from the pipeline would harm not only the lake's fish but also populations of other aquatic animals and plants.
But we already have a premise 2 which prevents the same point -> leakage

E) Since the beginning of the twentieth century, non native species of fish have been introduced into the lake and now make up a considerable proportion of its overall fish population.
This is a neutral arguments and provides a general information about the population of the lake and it is not concerned about the argument

HI GMATNinja , mikemcgarry , egmat , sayantanc2k, RonPurewal , DmitryFarber , MagooshExpert (Carolyn), ccooley , GMATNinjaTwo , SarahPurewal

Here we have to weaken technology is ineffective, there is fear too!!!

How would A weaken?
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hey NandishSS, my friend just would like to share my reasoning


So you have to weaken not the fact that the technology of pipiline is ineffective, but that installation of such pipile is ineffective. when weakening argument you need to find a additional reason that will undermine the argument. Yet, this reason should be relevant to the argument itself. look at aswer choices and pay close attenton to key words mentioned in the argument such as installation, pipilene, pollution So the major concern is the pollution and not the technology.

(A) The Pipeline's construction will disturb sediments at the bottom of the lake, dispensing into the water toxic pollutants that have settled there.
(A option talks about costruction i.e. installation that will cause toxic pollution. this is a reason that can weaken the argument. in other words, it will prove that despite leak preventing technology, the installation will still cause pollution.

(B) Changes in the land use and drainage patterns around the lake mean that the lake's waters are increasingly likely to be affected by agricultural runoff.

now look at this option, nowhere is mentioned agricultral runoff, we arent talking about irrigation, we are concerned about fish its out of scope.


(C) The leak-preventing technology has been in use for several years without any pipeline in which it is installed developing serious leaks.

Again C doesnt weaken argument cause it simply provides addittional but not contradictory information about leak-preventing techology.

(D) A major leak of oil from the pipeline would harm not only the lake's fish but also populations of other aquatic animals and plants.

D option just gives infirmation, saying that not only fish but other animals will suffer, but doesnt it weaken the installation of pipiline. it simply reiterates the information given in the argument by providing concomitant information (such as other animals)

(E) Since the beginning of the twentieth century, non native species of fish have been introduced into the lake and now make up a considerable proportion of its overall fish population.
this is just out of scope at all and not worth the discussion talking about species of fish, who cares. we talk about preventing pollution


Now when you have examined all options ask yourself which option would you choose through POE ?

Hi NandishSS!

The conclusion here is: "Fears that the fish population will decline with the construction of the new oil pipeline are groundless, because of this new technology which prevents oil leaks in the pipeline". We need to weaken this argument somehow. To weaken an argument, we want to identify the assumptions, and find one of them to refute. Here are a few assumptions that this argument makes:

1. Oil leaks are the sole cause of the fish population decline
2. The new technology will successfully prevent oil leaks

We only need to refute one of them in order to successfully weaken the conclusion; we don't have to address both or all of them (there are many other assumptions that we could consider). Choice A addresses the first assumption -- it tells us that there is another reason that construction of the oil pipeline could harm the fish population. Therefore, the new technology will not change the fact that the fish population will decline, since the new technology can only address oil leaks. So the new technology will be ineffective, and so the argument is invalid.

Does that make sense?
-Carolyn
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kinjiGC,

This is GMAT Prep question. I got it correct as option A but I did spend time on option C. Now I really want to understand what option C means exactly ? Part i.e "without any pipeline in which it is installed developing serious leaks " does not make sense to me ? "without any pipeline " is a typo ? Once you help me to understand the meaning with this abstract or half baked sentence then I will be read why C is wrong.

The passage is about construction of an oil pipeline across the lake's bottom. Fear is that the oil spill from the pipeline might again damage the lake. But then we are told that there is a technology which, if used effectively, will not let this leak happen. On the support of this technology, it is concluded that the fears are groundless.

We have to weaken the belief in this conclusion. We have to present more belief in the fact that the fears are not groundless, but are genuine. If this is so ,we need to find a scenario in which the oil pollution can take place even if the technology is effectively implemented. What if the technology itself become a cause of pollution. Or what if in order to prevent pollution by leak of oil from pipeline, we need to produce even more pollution. In such cases, the conclusion will not have much strength.

Looking at options :

A) This option is something similar to what I was able to think as a weaken scenario. I believe this is the correct choice.

B) I believe this option is mentioning about land use and changes in drainage patterns. How is that linked to the oil pipeline construction, especially when the construction is going to take place at the lake bottom and not on the land on the side. Has no impact the conclusion. Incorrect choice.

C) This option is trying to prove the effectiveness of the technology which is going to be used. Adds more to our confidence in it and hence also in the conclusion being drawn. Strengthens the conclusion. Incorrect choice.

D) This option tells us more about the severity of the pipeline leak. But this is something which we sort of already can understand. But how does that make us believe more in the fact that the pollution might happen even if the technology was effective. We have no clue. Incorrect choice.

E) Okay, so non-native species have grown rapidly in the lake. But how does it tell us that the leak might still happen despite using the technology to prevent leaks. We are not able to imagine a weakener in this option choice.

Correct answer option should be A.

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