Nihit wrote:
Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993, and as a result, nitrogen dioxide emissions have been significantly reduced throughout most of the country. Yet although the proportion of new cars in Donia's capital city has always been comparatively high, nitrogen dioxide emissions there have showed only an insignificant decline since 1993.
Which of the following, if true, most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia's capital city?
Argument - Catalytic converters (CC) --> reduce nitrogen dioxide (NO2) emissions.
- It is mandatory to fit CC in all new cars since 1993.
- Nationwide effect = NO2 emissions have decreased.
- Paradox = Nationwide there is a decrease, however, in capital city which has highest proportions of new cars has experienced a insignificant decline.
(A) More of the cars in Donia's capital city were made before 1993 than after 1993.
- The choice goes against the evidence given in the passage. The passage clearly states that proportion of new cars is higher than it is in entire nation.
- Wrong
(B) The number of new cars sold per year in Donia has declined slightly since 1993.
- These sales figures are immaterial. As long as the evidence of higher proportion of new cars is not refuted. The sales figures do not impact the argument
- Wrong
(C) Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.
- This option could have been a contender had the passage spoken about the percentage of nitrogen emission of the total emissions.
- However, the argument clearly mentions the absolute number.
- Wrong
(D) Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.
- The proportion of the owners with cars made before 1993 is less in the capital city. Hence, compared to the nation a fewer number of individuals with cars made before 1993 must have installed the CC.
- Thus we can say that the impact of decrease in NO2 emissions because of installing of CC in cars made before 1993 is higher in the entire nation compared to the impact in capital city.
- However we are not sure about the percentage of population owning cars made before 1993 that installed the CC.
- May be no one installed the CC, may be everyone installed the CC
- Wrong
(E) Most car trips in Donia's capital city are too short for the catalytic converter to reach its effective working temperature.
- If CC cannot reach its effective temperature --> it is not able to filter NO2 emissions - Explains the paradox
- Correct