Critical Reasoning

Lobsters and other crustaceans eaten by humans are more likely to contract gill diseases when sewage contaminates their water. Under a recent proposal, millions of gallons of local sewage each day would be rerouted many kilometers offshore. Although this would substantially reduce the amount of sewage in the harbor where lobsters are caught, the proposal is pointless, because hardly any lobsters live long enough to be harmed by those diseases.

Which one of the following, if true, most seriously weakens the argument.

(A) Contaminants in the harbor other than sewage are equally harmful to lobsters.
(B) Lobsters, like other crustaceans, live longer in the open ocean than in industrial harbors.
(C) Lobsters breed as readily in sewage-contaminated water as in unpolluted water
(D) Gill diseases cannot be detected by examining the surface of the lobster
(E) humans often become ill as a result of eating lobsters with gill diseases.

Ans is [spoiler](E)[/spoiler]
But i am not able to eliminate choice (B)[/img]

Authors argument is based on the fact that 'hardly any lobsters live long enough to be harmed by those diseases' but author does not consider that the infected lobsters may harm others i.t the human who will eat them. Option E clearly states this. Hence ans is E

Option B indirectly supports authors view. Because as per B 'Lobsters, like other crustaceans, live longer in the open ocean than in industrial harbors' i.e if the sewage is routed many kilometers offshore ,chances that lobsters will be harmed will be more as they live longer.So the proposal is pointless.

Thanks...makes sense.

Aren't we supposed to look at the conclusion specifically when we need to weaken an arguement?The conclusion states that "..the proposal is pointless...." The last sentence nowhere speaks about humans eating the lobsters.Then how is the OA E?

What does the author mean by rerouted offshore

offshore - far away from the coast where fishing doesnot happen
re-route - finding another way.

why did you ask this Munda?

HSPA wrote:offshore - far away from the coast where fishing doesnot happen
re-route - finding another way.

why did you ask this Munda?

i wanted to understand the impact of B on the conclusion and what effect would it have on the lobsters in the ocean .

@singalong : you are right in identifying conclusion : proposal is pointless.

But author has IGNORED the fact that these infected lobsters that will not die of the disease -- as they die before anyways -- may harm the humans who eat them.So we need to go with the proposal.

singalong wrote:Aren't we supposed to look at the conclusion specifically when we need to weaken an arguement?The conclusion states that "..the proposal is pointless...." The last sentence nowhere speaks about humans eating the lobsters.Then how is the OA E?

According to powerscore and other test prep companies , you must consider the information in the answer choices true in case of weaken questions

singalong wrote:Aren't we supposed to look at the conclusion specifically when we need to weaken an arguement?The conclusion states that "..the proposal is pointless...." The last sentence nowhere speaks about humans eating the lobsters.Then how is the OA E?

I think you have to assume the proposal was made by humans, for the benefit of humans. Hence the first part of the problem stating "lobsters and other crustaceans eaten by humans."

mundasingh123 wrote:According to powerscore and other test prep companies , you must consider the information in the answer choices true in case of weaken questions

here is a better way to know if you should consider the information true or not:

Which one of the following, if true, most seriously weakens the argument.

instead of thinking "if i see a 'weaken the argument' question, i should consider the answers to be true," think "if the question tells me to consider the answers true" i should...follow the directions.

@mundasingh123
thats a nice tip.

Lil...doesn't that depend on how the question is stated?I mean, for sure, do all weakening questions have "if true" in them?

IMO E

IMO E.

Where is the flaw in my logic for picking C:

People eating lobsters who live in contaminated waters will develop a gill disease. Since lobsters breed in sewage waters (as much as they do in unpolluted waters) rerouted IS needed to reduce/eliminate gill disease.

I understand this is not direct logic that hurts the conclusion but if this (breeding 50/50 factor) is known and could be averted not doing so will weaken the main conclusion.

Thanks!