In an effort to boost milk production, some dairy farmers

Question

In an effort to boost milk production, some dairy farmers are treating cows with a genetically engineered hormone called BST. Consumer groups have opposed the use of BST even though the milk of BST-treated cows is identical in nutritional value to that of untreated cows; the treated cows run a greater risk of infection and hence are more likely to be given antibiotics, which may show up in their milk. In high levels, these antibiotics may be harmful to humans. Yet the milk of treated and untreated cows alike is regularly screened for antibiotics.

Which one of the following is most strongly supported by the information above?

(A) Consumer groups have no legitimate reasons for opposing the use of BST.

(B) Milk from BST treated cows is as safe for human consumption as that from untreated cows.

(C) There is no advantage to the use of BST on dairy cows.

(D) Milk from BST-treated cows can be presumed safe for humans only if it is successfully screened for high levels of antibiotics.

(E) The only threat posed by drinking milk from cows treated with PST is high levels of antibiotics.

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sting8 · Answer

(A) Too strong. While some legitimate reasons (like nutritional value), are ruled out by the stimulus, there may be other reasons that aren't addressed.

(B) Too strong, again! There may be reasons it is less safe that weren't covered by the stimulus.

(C) Unsupported! The first line tells us that farmers are doing this in an effort to boost milk production. Now, we don't know whether it actually does boost production, but if it achieves that goal, this would be a potential advantage.

(D) This sounds good, but "only if" is really strong. That indicates that antibiotic screening is necessary for safety. Does our stimulus go that far? Well, we know BST can result in higher rates of antibiotic use. We also know that antibiotics can show up in the milk, and that high levels of antibiotics may be harmful to humans. So, if we didn't screen BST milk for antibiotics, we'd be at risk of getting high levels of antibiotics. Therefore the only way that milk can be presumed safe is if it is successfully screened. Bingo.

(E) Too strong, again! Antibiotics are the only threat that is discussed in this stimulus, but there could exist other threats that aren't covered here.

(Explanation from Manhattan)

ShreyasJavahar · Answer

(A) Consumer groups have no legitimate reasons for opposing the use of BST.
->Consumer groups could be protesting the side-effects of BST administration on the cows. Not particularly good to keep pumping them full of antibiotics. Out.

(B) Milk from BST treated cows is as safe for human consumption as that from untreated cows.
->Nowhere does the passage mention this, and without some idea of consumers' threshold for the tolerance of antibiotic percentage in milk, there's no way we can be sure of this. Out.

(C) There is no advantage to the use of BST on dairy cows.
->Milk production is boosted by the use of BST. Additionally, if the antibiotic screening test comes out fine for the BST treated cow's milk, sales are boosted as well, and consumers may very well pay lesser for milk. C is wrong. Out.

(D) Milk from BST-treated cows can be presumed safe for humans only if it is successfully screened for high levels of antibiotics.
->Pretty much what we've been looking for. The one caveat that will green-light the BST treatment process. Passage says that the milk may contain a high concentration of antibiotics that MAY prove harmful to humans. D tells us that using a different test, one that tests for higher concentrations of antibiotics, will help us determine whether BST milk is good to go or not. The passage strongly supports this line of reasoning. D it is.

(E) The only threat posed by drinking milk from cows treated with PST is high levels of antibiotics.
->Infected cows could pass on the infection causing bacteria that the antibiotics might not have killed, some stronger strains of bacteria that have adapted to the antibiotics could very well be present in the milk and could potentially pose a threat. Out.

sssanskaar · Answer

Option D it is.

Milk from BST treated cows can not be presumed as safe if no screening has been done.

Crytiocanalyst · Answer

(A) Consumer groups have no legitimate reasons for opposing the use of BST.
They have a legitimate reason that's high level of antibiotics -hence out

(B) Milk from BST treated cows is as safe for human consumption as that from untreated cows.
Nope high concentration of antibiotics can make it hramful for human consumption - Hence out

(C) There is no advantage to the use of BST on dairy cows.
High milk production is a advantage we can infer from the passage - Hence out

(D) Milk from BST-treated cows can be presumed safe for humans only if it is successfully screened for high levels of antibiotics.
This is exactly what we can infer from the passage - Hence let us hang on to it

(E) The only threat posed by drinking milk from cows treated with PST is high levels of antibiotics
/We/ are not in a position to comment on the same with the given premise- Hence out 
Therefore IMO D

abhishekmayank · Answer

I think that option D is violating the basic principle of CR :

(D) Milk from BST-treated cows can be presumed safe for humans only if it is successfully screened for high levels of antibiotics.

In the premise :

Antibiotics in high level --> Harmful

In a basic principle of CR, we can't conclude that -

Not high level of antibiotics --> Not harmful (safe)

unraveled · Answer

abhishekmayank 
You are right to point out the principle. However, the language in D is not in the form of absoluteness. It basically points to scope wherein higher levels of BST are yet not successfully screened. I can bet 'successfully' surely means to the benefits of consumers. 
Also, the word 'presumed' is placed safely which doesn't mean  Not high level of antibiotics --> Not harmful (safe) .
For me, three words - presumed, only and successfully - are the key in D.

Besides all this, others are nowhere and D is relatively safe to choose.

Answer D.

VerbalBot · Answer

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In an effort to boost milk production, some dairy farmers

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