From 1970 to 1990, sea otters made up a steadily decreasing percentage

Question

From 1970 to 1990, sea otters made up a steadily decreasing percentage of the marine life population in North America. The increasingly widespread effects of pollution and habitat destruction were responsible for this decrease. However, although pollution was a more frequent target of environmental legislation, it was found that pollution in North America increased by a greater percentage than did the rate of habitat destruction.

Which of the following, if true, most helps to account for the finding?

(A) Environmental legislation limiting industrial pollution was much more financial onerous on North American firms than legislation protecting marine habitats.

(B) The decreasing percentage of sea otters among the marine population had a positive effect on the species that sea otters typically prey on.

(C) Most of the habitats likely to be destroyed by human activity had already been compromised for marine life by 1970.

(D) Habitat destruction was a more frequent target of environmental legislation than pollution in the decade preceding 1960.

(E) Marine life as a whole was more significantly affected by pollution than by habitat destruction.

GH-12.11.12 - OE to follow

akhil911 · Accepted Answer

I believe that the only point of confusion is between B and C here.
Let me try and put together an explanation on why C is much better than B.

(B) The decreasing percentage of sea otters among the marine population had a 
positive effect on the species that sea otters typically prey on.
This point talks about sea otters population going down and some other species population growing but it does not talk about the habitat destruction that has taken place.
A part of this answer choice just states the premise but the other part does not give any support to the conclusion.

(C) Most of the habitats likely to be destroyed by human activity had already been
compromised for marine life by 1970.
In this answer choice , when the author says that say 50% of the habitat was already destroyed before 1970 then only 50% more is left to be destroyed in the years to come and hence the rate of destruction is lower when compared to if we started with 100%.

Hope i have been able to shed some light on the confusion in these two options.

roopika2990 · Answer

Nice one ...I was confused between B & C ... finally chose B since the negative impact of sea otters on marine life was reduced by the positive impact of its prey ... But I guess C is also fine

akashb106 · Answer

(A) Environmental legislation limiting industrial pollution was much more financial 
onerous on North American firms than legislation protecting marine habitats. -----  This tells us financial information. But does not give us any information on why was pollution increase greater than habitat destruction.

(B) The decreasing percentage of sea otters among the marine population had a 
positive effect on the species that sea otters typically prey on. -----  Does not specify the species and how much do the species affect the habitat. This answer is the closest but I feel there are a lot of loopholes for this to be the answer.   (A better explanation would be much appreciated)

(C) Most of the habitats likely to be destroyed by human activity had already been
compromised for marine life by 1970. -----  CORRECT because most of the habitat was already destroyed before. So the rate of habitat destruction is going to be less than that of pollution

(D) Habitat destruction was a more frequent target of environmental legislation than 
pollution in the decade preceding 1960. ----  No information about the increase in the current decade. Trying to imply that because habitat destruction was a frequent target in the previous decade, the increase is lower in this decade.

(E) Marine life as a whole was more significantly affected by pollution than by habitat destruction.  Out of scope.

Kathiresan · Answer

Hiiiii

I was confused between B & C before looking into the answer. Was convinced with C only after the explanation...

avohden · Answer

Official Explanation

Answer: C   When a question asks you to "account for a finding," the finding itself must be somewhat unexplained, even a paradox. In this case, we know there are two causes for the decrease in the otter population: pollution and habitat destruction. Because legislation has had more to say about pollution, it makes sense that the effects of pollution would go down, meaning that habitat destruction is the bigger problem. But the argument tells us that pollution remains the bigger problem. Choice (A) doesn't help--the cost of the legislation doesn't tell us about its effectiveness. (B) is irrelevant, as we care only about sea otters. Similarly, (E) is too general. Choice (C) is correct. If habitat destruction had almost reached its maximum by 1970, it's only reasonable that it didn't increase by a very large percentage between 1970 and 1990. (E) may sound similar, but it is less directly related. Not only does it discuss legislation (not the specific destruction of habitats), but the endpoint is 1960, not 1970, as it is in the question and in (C).

Hope this helps.

deveshj21 · Answer

Moreover option E is the conclusion that can be inferred from the passage, and conclusion cannot tell us anything regarding the underlying issues.

Posted from my mobile device

Harshjha001 · Answer

I didn't choose the answer C because i thought that while we deal with percentage , we take current value as 100 and then calculate it . How does it matter what was the past value ? even if 50% of habitat was destroyed in 1970 , the current 50 % will be treated as 100 % and then the change(delta ) will be calculated . 
1970 is the base of consensus has not been mentioned anywhere so if the population changes by 10% from 100 to 110 , it is in reference to current year . Until it is mentioned that 1970 has been taken as base year for % calculation.
Can someone please tell me where i went wrong ?

Dooperman · Answer

A, B and E are irrelevant. 
Only C and D make sense.

Between C and D, as both talk about something that happened in the past and try to present that thing as a reason for the current paradox.

But D has less strength as it talks about a time preceding 1960s and doesn't tell about what happened in 1960s.

C is much more logical.

VerbalBot · Answer

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From 1970 to 1990, sea otters made up a steadily decreasing percentage

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