Nitrogen dioxide is a pollutant emitted by automobiles.

Question

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
althouth 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?

A. More of the cars in Donia’s capital city were made before 1993 than after 1993.
B. The number of new cars sold per year in Donia has declined slightly since 1993
C. Pollutants other than nitrogen dioxide that are emitted by automobiles have also
been significantly reduced in Donia since 1993.
D. Many Donians who own cars made before 1993 have had catalytic converters
installed in their cars.
E. Most car trips in Donia’s capital city are too short for the catalytic converter to
reach its effective working temperature.

AVakil · Answer

I am going with choice A here. This is the only choice that describes a specific enough reason as to why there was no effect in the capital city.

testgmat · Answer

I will go with E

dynamo · Answer

IMO E.

GMATBLACKBELT · Answer

E.

A doesnt explain why there has been little reduction if any. It could explain a less than expected reduction, but not a practically non-existant reduction.

hanumayamma · Answer

Conclusion: Which of the following most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia’s capital city?

A. More of the cars in Donia’s capital city were made before 1993 than after 1993. ( Hold it )
B. The number of new cars sold per year in Donia has declined slightly since 1993 ( The argument discusses the measures taken by the new cars to reduce the nitrogen emissions, but does not directly discusses the sales of the new cars – eliminate it )
C. Pollutants other than nitrogen dioxide that are emitted by automobiles have also
been significantly reduced in Donia since 1993. ( This is outside of the scope of the argument. – eliminate it )
D. Many Donians who own cars made before 1993 have had catalytic converters
installed in their cars. ( This weakens the argument – eliminate it )
E. Most car trips in Donia’s capital city are too short for the catalytic converter to
reach its effective working temperature. ( This answer choice sounds close, but requires an extra assumption that short trips are prevalent in the Donia. Since nothing regarding the short trips is mentioned, eliminate it .)

Answer: A

marcodonzelli · Answer

A. the argument says that "the proportion of new cars in Donia’s capital city has always been
comparatively high". A contradicts the argument.
B. we don't know if these cars substitute the old ones
C. out of scope
D. it could be, but many doesn't mean most
E. I believe it is the correct choice

buffdaddy · Answer

To paraphrase the argument.

- Cars omit NO2 that pollutes the air
- Cat converters reduce NO2 emissions
- Cat converters a requirement on new cars since 1993
- In the whole country, NO2 emmisions reduced a LOT since 1993, except Donia
- Most of Donia's cars are new, i.e have Cat converters

To explain the above we have to choose an option which poses a situation where the Cat converters do not work in reducing NO2 in new cars.

now for the options

A) this says something that is completely opposite to a FACT in the arguement. Eliminate
B) if the number of new cars sold has declined slightly, but new cars are still sold. It is not a concrete explaination.
C) Irrelevant since we only need to find an explanation about why NO2 levels have only slightly gone done.
D) This is the opposite of the explanation we are looking for. If this were the case, Donia would have seen major reductions of NO2
E) This options mentions that short trips are prevelant, and we have to take this as the TRUTH, since this is extra facts that are now made available to us. CORRECT because it explains why NO2 has only gone down slightly. Since most trips are short, Cat converters do not come into play at all. Some trips are still long, and so after the new law came in, these longer trips produce lower amounts of NO2, bringing the levels down slightly.

E is the answer

maratikus · Answer

E looks right.

JCLEONES · Answer

Folks,

E is the OA. I will post another intersting CR.

Nitrogen dioxide is a pollutant emitted by automobiles.

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