Ethicist: On average, animals raised on grain must be fed

+1 for B

Ya ur explanation was convincing...
Also i was confused between B and D.

Can u explain why not D?

The argument mentions the premise and then the author CONCLUDES. The conclusion can be weakened if we show beyond reasonable doubt that the CONCLUSION does not logically follow from the premise..

Borriwing from JP27

Premise


Conclusion:


Grain yields have leveled..Large agriculture areas are going out of business, and we have a population that is expanding..

One way to look at this is to ask oneself "Why has the author concluded this" ... Obviously in this case the author is arguing that the cattle and cattle farming is putting a burden on the soil which could have been used to grow grain (in the sense that the grain is being produced for the CATTLE rather then for humans), that could otherwise feed many more people...Therefore the Answer choice B is correct because it tackles this conclusion in that it introduces a new PREMISE with the addition of which the CONCLUSION has become totally erroneous.

D is wrong because it is out of scope. Although the author does breifly mention declining agriculture land, he's linking LAND that can grow grains to feed HUMANS vs an alternative use of that land to farm cattle. His conclusion is therefore resting on this very premise. Therefore any additional information that does not mention this link does nothing to weaken the conclusion and the argument in general.

Hope it helps..

BTW (B) is the OA...

Hmmm thanks vomhorizon...

Clear explanation... made me understand....

I'm facing difficulties with CR ...
Not able to get through difficult ques

All you have to remember in WEAKEN questions is that the Author's CONCLUSION needs to be weakened..and the way to weaken that conclusion is to find an alternate conclusion based on the premise. Even if the conclusion is erroneous, we have to assume that the AUTHOR based his conclusion on the premise (s) and Believed in it 100%. Therefore any choice that cannot blend in with the Premise ----> Conclusion connection is Incorrect. Other wrong answers may be Paraphrases of existing premise, or a choice that may be totally out of scope (other then the obvious ones which either Strengthen the conclusion or leave it unchanged - those are generally easy to spot).. Critical reasoning although involves a lot of Logic, can be improved upon if you Establish the Rules and Methodology that is laid down by most Text books (I prefer the Power score Logic reasoning LSAT book)..Just remember each CR question type is essentially a different concept and involves a different approach.

Ya i agree with u....
Each CR is different....
Gotta learn a lot....
hmmm thanks dude....

Wow! I ended up choosing E, but after seeing vomhorizon words above is clearly very far away from the conclusion. E is out-of-escope, as it does not address the issue of land usage.

Ethicist: On average, animals raised on grain must be fed sixteen pounds of grain to produce one pound of meat. A pound of meat is more nutritious for humans than a pound of grain, but sixteen pounds of grain could feed many more people than could a pound of meat. With grain yields leveling off, large areas of farmland going out of production each year, and the population rapidly expanding, we must accept the fact that consumption of meat will soon be morally unacceptable.

Which one of the following, if true, would most weaken the ethicist’s argument?

(A) Even though it has been established that a vegetarian diet can be healthy, many people prefer to eat meat and are willing to pay for it. --If meat itself won't be available then how will the people pay for it?

(B) Often, cattle or sheep can be raised to maturity on grass from pastureland that is unsuitable for any other kind of farming. --Correct. If the cattle can be fed on sources other than farmland grain then meat will be readily available.

(C) If a grain diet is supplemented with protein derived from non-animal sources, it can have nutritional value equivalent to that of a diet containing meat. --This strengthens the argument

(D) Although prime farmland near metropolitan areas is being lost rapidly to suburban development, we could reverse this trend by choosing to live in areas that are already urban. --"Could" is a hypothetical scenario.

(E) Nutritionists agree that a diet composed solely of grain products is not adequate for human health. --This option talks about grain products and not about meat.

Option(B) definitely weakens the conclusion.

But doesn't option (D) also weaken the conclusion to an extent? The stimulus clearly mentions that large areas of farmland are going out of production, so if the people leave these areas and allow animals to be reared here, then there is a good chance more meat can be produced. Am I thinking along the right lines?

@abjijay,

D doesn't really weaken the conclusion. The conclusion tells us that it might become morally unacceptable to eat meat because farmland gets lost because of overusage. D, however, only provided us with the information that humans can mitigate reduction of farmland by suburban development. But if the human race mitigates this kind of farmland reduction, the other kind of reduction due to farmland overusage doesn't get precluded. Hence, the reduction will still go on and it will be likely that consuming meat will be morally unacceptable.

Hope that help

Thanks Masterscorp for the explanation! I'll add my two cents, just in case it helps to hear things phrased another way...

Yes, if (D) is true, we might be able to slow the loss of prime farmland near metropolitan areas. But this refers to a very specific subset of the total farmland. Even if we save some prime farmland near metropolitan areas, total farmland could still increase, decrease, or stay the same. Without more information, we don't know whether (D) will help mitigate the farmland issue.

And we still have to contend with the fact that the population is rapidly expanding and the fact that sixteen pounds of grain could feed many more people than could a pound of meat.

The only way that (D) weakens the conclusion is if the amount of farmland saved by living in urban areas is enough to INCREASE total farmland to levels that can sustain the increasing demand for food. Without more information, (D) must be eliminated. I hope that helps!

Can someone tell me why E is wrong?

"We must accept the fact that consumption of meat will soon be morally unacceptable" - notice that the author does NOT say that people should eat ONLY grain! The author simply says that consumption of meat will soon be morally unacceptable.

According to the author, it would be morally acceptable to eat grains, fruits, vegetables, beans, and any other non-meat food products. A diet composed solely of grain products may not be adequate for human health, but a diet composed of grain products AND other non-meat products might be adequate.

Without further information, (E) does not weaken the author's argument.

I hope this helps!

please tell me why option E is wrong

The post directly above yours does that in detail. Let us know if you have a specific question about it!