apramanik wrote:
Since the passage of the state’s Clean Air Act ten years ago, the level of industrial pollutants in the air has fallen by an average of 18 percent. This suggests that the restrictions on industry embodied in the act have worked effectively. However, during the same period the state has also suffered through a period of economic decline. The number of businesses in the state has fallen by 10 percent, and the number of workers employed has fallen by 12 percent. It is probable that the business decline, rather than the regulations in the act, is responsible for at least half of the decline in the pollution.
Which of the following, if true, would most seriously weaken the conclusion drawn in the passage above?
(A) During the last ten years, economic conditions in the nation as a whole have been worse than those within the state.
(B) Amendments to the Clean Air Act that were enacted six years ago have substantially strengthened its restrictions on industrial air pollution.
(C) Of the businesses that ceased operating in the state during the last ten years, only 5 percent were engaged in air-polluting industries.
(D) Several large corporations left the state during the last ten years partly in order to avoid compliance with the Clean Air Act.
(E) Due to its small budget, the state office charged with enforcement of the Clean Air Act has prosecuted only two violators of the law since its passage.
Clean air act was passed 10 yrs ago.
Pollutants in the air fallen by 18 percent
During the same period the state has also suffered through economic decline - number of businesses has fallen by 10%.
Conclusion: Business decline, and not the act, is responsible for at least half of the decline in the pollution.
Because business declined by 10%, we are concluding that at least 9% of pollutants decline happened because of this, not the act.
We need to weaken this. So we need to say that the pollutant decline due to business decline may be of the order of less than 9%.
(A) During the last ten years, economic conditions in the nation as a whole have been worse than those within the state.
Irrelevant
(B) Amendments to the Clean Air Act that were enacted six years ago have substantially strengthened its restrictions on industrial air pollution.
Doesn't help us change our numbers.
(C) Of the businesses that ceased operating in the state during the last ten years, only 5 percent were engaged in air-polluting industries.
Correct. The conclusion is claiming that more than 9% of pollution decline can be attributed to business decline but the polluting businesses comprised of only 5%. The others were anyway non polluting. Then their shutting down will have no impact on pollution levels. So we can attribute less than 9% to business decline.
(D) Several large corporations left the state during the last ten years partly in order to avoid compliance with the Clean Air Act.
Were these large corporations causing pollution? We don't know. Note that the option above helps us bring this point to the fore. Even if it doesn't hit us on its own, option (C) helps us realise that we don't know whether these corporations were pollution causing. Perhaps they did not cause pollution at that time but wanted to set up some new processes but clean air act would not have allowed them to so they moved. We don't know. Point is, this option doesn't give us enough information to evaluate while option (C) is quite clear.
(E) Due to its small budget, the state office charged with enforcement of the Clean Air Act has prosecuted only two violators of the law since its passage.
If anything, it shows that clean air act may not be strictly enforced and hence may not be strictly followed.
Answer (C)
Kindly help to clear my doubt.
Option C states 'of the businesses that ceased operating in the state during the last ten years, only 5 percent were engaged in air-polluting industries'.
What if this 5% that was engaged in air polluting activities was the highest contributor to air pollution?
Suppose the 5% contributed to more than 9% in pollutants.
5% Industries engaged in air pollution can have a larger share in causing air pollution. So, we can attribute this change in air pollution level to economic slowdown.
Thank you.