- Tue Jan 20, 2009 12:00 am
#36683
Complete Question Explanation
Weaken—CE. The correct answer choice is (B)
Many test takers enjoy Weaken questions because these questions necessitate the use of skills often
required in real-world situations. Test takers are quite accustomed to finding inconsistencies, loopholes,
flaws, and shortcomings in other people’s arguments and these abilities can prove to be quite useful
on the LSAT. Such test takers may think of several different ways to attack this argument. Remember,
however, that the test makers will almost never attack the premises in a Weaken question. It is very
unlikely that the correct answer choice will say, “Today’s farmers actually plant many different strains
of a given crop,” or, “No known disease exists which would strike only a few strains of crops.” Rather
than questioning the author’s evidence, the correct answer will attack the author’s use of that evidence in
drawing a conclusion.
Here, the author uses the evidence to make two claims. First, a disease that strikes only a few strains of
crops would have had only minor impact on the food supply in the past. Second, such a disease would
devastate the food supply today. It should be obvious that the latter claim is the author’s main argument.
So the primary objective is to find an answer choice which proves that this disease would not devastate
the food supply.
Answer choice (A): This statement would only contradict the author’s secondary claim (and not the
conclusion) if the crop diseases mentioned here struck only a few strains of crops. It is possible that the
devastating crop diseases mentioned in answer choice (A) are different than the disease(s) that strikes
only a few strains of crops mentioned in the stimulus. Hence, this answer choice does not attack the
author’s conclusion.
Answer choice (B): This is the correct answer choice. This answer choice requires a number of
assumptions. First, “quickly” must mean that the replacement crops can be used before the food supply
becomes devastated, otherwise the conclusion could still be correct. Also, some of the strains among the
many strains stored in the seed banks must not be affected by the disease. Finally, replacing the affected
crops must not itself be devastating to the food supply. If all these things are true, then the author’s
argument would be weakened. While not the most clear Weaken answer choice on the test, this is the
strongest answer choice available.
Answer choice (C): If this is true, it probably strengthens the author’s argument by adding evidence that
popular seed strains used today are less resistant than some of the less popular strains used previously.
Answer choice (D): The increased variety of human diets, and a heavy reliance on rice and wheat, does
not suggest that the food supply would not be devastated by a crop disease. In fact, an argument could
be made that this choice potentially strengthens the conclusion, as a heavy reliance on specific crops
could theoretically result in the devastation of the food supply if those specific crops (rice and wheat
in this example) were wiped out by disease. Because there is nothing to suggest that wheat and rice are
particularly invulnerable to disease, or that they would likely not be devastated in the event of a disease
outbreak, this answer choice certainly does not weaken the conclusion.
Answer choice (E): While it may be comforting to know that today’s crops are more pest- and weedresistant
than they once were, this knowledge does not weaken the author’s argument. Remember, the
author is only concerned with the devastating impact of disease upon today’s overly homogenous crop
strains, and crops’ resistance to other threats does nothing to offset their susceptibility to disease.
Thus, answer choice (B) is the only remaining Contender. It may not be perfect, but it is the only answer
choice which could plausibly weaken the author’s claim.
Weaken—CE. The correct answer choice is (B)
Many test takers enjoy Weaken questions because these questions necessitate the use of skills often
required in real-world situations. Test takers are quite accustomed to finding inconsistencies, loopholes,
flaws, and shortcomings in other people’s arguments and these abilities can prove to be quite useful
on the LSAT. Such test takers may think of several different ways to attack this argument. Remember,
however, that the test makers will almost never attack the premises in a Weaken question. It is very
unlikely that the correct answer choice will say, “Today’s farmers actually plant many different strains
of a given crop,” or, “No known disease exists which would strike only a few strains of crops.” Rather
than questioning the author’s evidence, the correct answer will attack the author’s use of that evidence in
drawing a conclusion.
Here, the author uses the evidence to make two claims. First, a disease that strikes only a few strains of
crops would have had only minor impact on the food supply in the past. Second, such a disease would
devastate the food supply today. It should be obvious that the latter claim is the author’s main argument.
So the primary objective is to find an answer choice which proves that this disease would not devastate
the food supply.
Answer choice (A): This statement would only contradict the author’s secondary claim (and not the
conclusion) if the crop diseases mentioned here struck only a few strains of crops. It is possible that the
devastating crop diseases mentioned in answer choice (A) are different than the disease(s) that strikes
only a few strains of crops mentioned in the stimulus. Hence, this answer choice does not attack the
author’s conclusion.
Answer choice (B): This is the correct answer choice. This answer choice requires a number of
assumptions. First, “quickly” must mean that the replacement crops can be used before the food supply
becomes devastated, otherwise the conclusion could still be correct. Also, some of the strains among the
many strains stored in the seed banks must not be affected by the disease. Finally, replacing the affected
crops must not itself be devastating to the food supply. If all these things are true, then the author’s
argument would be weakened. While not the most clear Weaken answer choice on the test, this is the
strongest answer choice available.
Answer choice (C): If this is true, it probably strengthens the author’s argument by adding evidence that
popular seed strains used today are less resistant than some of the less popular strains used previously.
Answer choice (D): The increased variety of human diets, and a heavy reliance on rice and wheat, does
not suggest that the food supply would not be devastated by a crop disease. In fact, an argument could
be made that this choice potentially strengthens the conclusion, as a heavy reliance on specific crops
could theoretically result in the devastation of the food supply if those specific crops (rice and wheat
in this example) were wiped out by disease. Because there is nothing to suggest that wheat and rice are
particularly invulnerable to disease, or that they would likely not be devastated in the event of a disease
outbreak, this answer choice certainly does not weaken the conclusion.
Answer choice (E): While it may be comforting to know that today’s crops are more pest- and weedresistant
than they once were, this knowledge does not weaken the author’s argument. Remember, the
author is only concerned with the devastating impact of disease upon today’s overly homogenous crop
strains, and crops’ resistance to other threats does nothing to offset their susceptibility to disease.
Thus, answer choice (B) is the only remaining Contender. It may not be perfect, but it is the only answer
choice which could plausibly weaken the author’s claim.