According to a prediction of the not-so-distant future published in 19

Question

According to a prediction of the not-so-distant future published in 1940, electricity would revolutionize agriculture. Electrodes would be inserted into the soil, and the current between them would kill bugs and weeds and make crop plants stronger.

Which of the following, if true, most strongly indicates that the logic of the prediction above is flawed?

(A) In order for farmers to avoid electric shock while working in the fields, the current could be turned off at such times without diminishing the intended effects.

(B) If the proposed plan for using electricity were put into practice, farmers would save on chemicals now being added to the soil.

(C) It cannot be taken for granted that the use of electricity is always beneficial.

(D) Since weeds are plants, electricity would affect weeds in the same way as it would affect crop plants.

(E) Because a planting machine would need to avoid coming into contact with the electrodes, new parts for planting machines would need to be designed

AnishPassi · Accepted Answer

The Story     
 According to a prediction of the not-so-distant future published in 1940, electricity would revolutionize agriculture.  – There was a prediction that electricity would revolutionize agriculture.  (I’m wondering how it would do that. Perhaps the answer will follow.)

Electrodes would be inserted into the soil, and the current between them would kill bugs and weeds and make crop plants stronger . – Electrodes would be used to kill bugs and weeds and make crop plants stronger.  (Aha. This statement indeed explains how electricity would revolutionize agriculture.)

Prediction’s logic: 
It was predicted that electricity would revolutionize agriculture.
How? Electrodes would be inserted into the soil. Current will be passed between them. This current would kill bugs and weeds, making crop plants stronger.

Gap(s) in logic: 
What if electricity harms the crop plants as well?

Question Stem

Which of the following, if true, most strongly indicates that the logic of the prediction above is flawed?

Framework: 
What is the prediction?
That electricity will revolutionize agriculture.

What’s the logic?
Electrodes would be used to kill bugs and weeds and, thereby, make crops stronger. So, fewer bad things (bugs and weeds) and a good thing (stronger crop plants). That’s how electricity will revolutionize agriculture.

We have to look for something that will indicate a flow in the logic. Essentially, something that indicates that even if electrodes are used, electricity would not revolutionize agriculture.

Prediction: 
Electricity will harm the crop plants too.

Answer choice analysis

A. In order for farmers to avoid electric shock while working in the fields, the current could be turned off at such times without diminishing the intended effects. 
  Incorrect  .So farmers can work without worrying about electricity and the intended effects won’t be impacted either. That seems to be a good thing. Not a flaw in the logic.

B. If the proposed plan for using electricity were put into practice, farmers would save on chemicals now being added to the soil. 
  Incorrect  . Another benefit of using electricity. Again seems that electricity will truly revolutionize agriculture. Not a flaw in the logic.

C. It cannot be taken for granted that the use of electricity is always beneficial. 
  Incorrect  . Ok, So electricity need not always be beneficial. But, electricity could very well still be beneficial in agriculture. The prediction is not based on the logic that since electricity is always beneficial, therefore it will be beneficial in agriculture too. Is this a flaw in the prediction’s logic? No.

D. Since weeds are plants, electricity would affect weeds in the same way as it would affect crop plants. 
  Correct  . This one is in line with our prediction.
 “Same way” Indicates that plants would get killed as well. If electricity (electrodes) will kill crop plants as well, perhaps electricity  will not  revolutionize agriculture. This statement highlights a flaw in the logic of the prediction.

E. Because a planting machine would need to avoid coming into contact with the electrodes, new parts for planting machines would need to be designed 
  Incorrect  . So, using electrodes will require some additional work. Planting machines would need new parts, and such parts would need to be designed.
This statement indicates a potential reason for not going ahead with using electricity in agriculture. So, it can be considered a weakener for the prediction. It does not, however, indicate a flaw in the logic of the prediction. The logic that electrodes will benefit plants (kill bugs and weeds, and thereby make crop plants stronger) and therefore electricity will revolutionize agriculture remains intact.

Additional Notes     
1. The question stem asks us to find an answer choice that ”most strongly indicates that the logic of the prediction above is flawed”. We need to find a flaw in the logic, and not find an alternate reason for why electricity might not revolutionize agriculture. If using electricity in agriculture requires additional work (option E), I might start doubting whether electricity will revolutionize agriculture (the prediction). The option does not, however, indicate a flaw in the logic of the prediction.

E.g.,

John is driving an expensive car. Therefore, John is rich.

A. John lives in a very poor community.
Does this option highlight a flaw in the argument’s logic? No. The argument is not based on where John lives.
Does it weaken the argument? Yes. Now I believe less that I did before that John is rich.

B. John does not own the car.
Does this option highlight a flaw in the logic? Yes. The argument’s logic was based on the assumptions that anyone driving an expensive car perhaps owns it. And anyone who owns an expensive car is rich. 
Does it weaken the argument? Yes. Now I believe less that I did before that John is rich because this answer choice attacks the logic.

2. One could argue that option D contradicts the passage and is therefore wrong.

Here’s how:

In the last sentence there’s a prediction that the current between the inserted electrodes would 
a. kills bugs and weeds
b. and make crop plants stronger

Option D states that ”electricity would affect weeds in the same way as it would affect crop plants”. So, presumably electricity would kill weeds as well as crop plants. Thus the current between the inserted electrodes  will not make crop plants stronger.

So, one could argue that “since we’re given that the current would make crop plants stronger, whereas this option indicates that the current would kill crop plants, this option is wrong.”

Such reasoning is wrong.

Firstly, the question stem includes the phrase ”if true”. So, our job is not to check the validity of the answer choices. Rather, we have to accept them as true and then check whether they answer the question.

Secondly, notice that the last sentence of the passage is also a prediction. Predictions always have inherent assumptions. E.g., you might be thinking “I will prepare for GMAT for at least one more hour today.”
Can you be sure though? While hopefully nothing happens to break your rhythm, can you be 100% certain that you  will  prepare for at least one more hour today? No, right? You might get an important work call, you might have a family issue that needs to be dealt with immediately, you might have a friend call you and ask for urgent help, you might just feel lazy.

Predictions have an inherent assumption that all things will go according to plan. And that assumption can be challenged.

thevenus · Answer

(A) In order for farmers to avoid electric shock while
working in the fields, the current could be turned
off at such times without diminishing the
intended effects.
 neutral effect on the argument.

(B) If the proposed plan for using electricity were
put into practice, farmers would save on
chemicals now being added to the soil.
 strengthening

(C) It cannot be taken for granted that the use of
electricity is always beneficial.
 it is too generic to weaken the argument.

(D) Since weeds are plants, electricity would affect
weeds in the same way as it would affect crop
plants.
 weakening ; the main crop plant will be killed along with the weeds and bugs.
 
(E) Because a planting machine would need to avoid
coming into contact with the electrodes, new
parts for planting machines would need to be
designed.
 weakening but the magnitude of weakness is lower than that of (D)

crackHSW · Answer

Its a clear D , as it states that electrodes will affect the plants and weeds equally so only weeds would not be killed, plants along with weeds would be killed as well

AKG1593 · Answer

Option D seems appropriate weakener.
The argument says current would kill weeds and strengthen crops.What if weeds were crop plants too?The current will have same effect on both.

Posted from my mobile device

azargoshtasb · Answer

I have no doubts that OA is D, but in part of the premises the author states that "... kill bugs and weeds" and then concludes that " make crop plants stronger". 
OA D states the exact opposite! 
any explanations?!!@

deep14 · Answer

Hi Azargoshtab. In flaw type questions you have to identify the flaw in the reasoning between two premises. In other words you have to attack the assumption without caring much for the premises. Here the assumption is that this method will not have any similar adverse effect on crops. If this assumption is true then we can safely say that this method will kill the weeds and bugs, and therefore will make the crops stronger. But since this assumption is not made in the argument we can attack it through option D. Hope this helps :-D

StaicyT · Answer

premise:
 
answer:
 
totally agree with  azargoshtasb  - there is obvious flaw in logic.

deep14 , to find flow in logic doesn't mean to make premise wrong..it means to find the fact which makes conclusion wrong. am I right?

chesstitans · Answer

the pattern in this question is important. Many reliable sources have been adding such pattern in their pools of gmat questions.

D directly links with the argument.

VerbalBot · Answer

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According to a prediction of the not-so-distant future published in 19

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