Last visit was: 19 Nov 2025, 10:54 It is currently 19 Nov 2025, 10:54
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
vv65
Joined: 01 Mar 2015
Last visit: 10 Nov 2025
Posts: 534
Own Kudos:
395
 [1]
Given Kudos: 774
Location: India
GMAT 1: 740 Q47 V44
GMAT 1: 740 Q47 V44
Posts: 534
Kudos: 395
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
freemanfanmao
Joined: 17 Oct 2022
Last visit: 10 Mar 2023
Posts: 11
Own Kudos:
3
 [1]
Given Kudos: 5
Posts: 11
Kudos: 3
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
vv65
Joined: 01 Mar 2015
Last visit: 10 Nov 2025
Posts: 534
Own Kudos:
Given Kudos: 774
Location: India
GMAT 1: 740 Q47 V44
GMAT 1: 740 Q47 V44
Posts: 534
Kudos: 395
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
GMATNinja
User avatar
GMAT Club Verbal Expert
Joined: 13 Aug 2009
Last visit: 19 Nov 2025
Posts: 7,443
Own Kudos:
69,786
 [1]
Given Kudos: 2,060
Status: GMAT/GRE/LSAT tutors
Location: United States (CO)
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Products:
Expert
Expert reply
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Posts: 7,443
Kudos: 69,786
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
freemanfanmao
GMATNinja

The explanation you quoted is spot-on. The passage very clearly indicates that there's a big difference between (1) what happened in the capital and (2) what happened in most of the country. Why is it that NO2 emissions barely declined in the capital while NO2 emissions were significantly reduced throughout most of the country?

(D) fails to explain that difference. All else being equal, we would expect (D) to have the same impact on emissions everywhere in the country (including the capital). After all, if (D) is true, then ANY car (new or old) can have a catalytic converter and thus can have lower NO2 emissions. That means that the new tech should lower NO2 emissions everywhere, regardless of the proportion of pre-1993 vehicles... so why the discrepancy in the data?

(E) is the only one that explains the difference, so it's the only choice that works.

I hope that helps!
Thanks Charles for the reply and confirmation. So if (D) said "Many Donians in the capital who own cars made before 1993 have had catalytic converters installed in their cars.", then it would be a possible correct answer to the question right?

Thanks.
In general, it's not worth changing answer choices and assessing the versions that you've developed. Your task is to evaluate the answer choices on the page, so it's not a great use of your time to come up with your own versions.

Even with the change that you've made, (D) doesn't explain why NO2 emissions haven't gone down that much. We'd also need to know when these capital-dwellers installed the catalytic converters to make a meaningful assessment. If they were installed before 1993, then your adapted answer choice might explain why NO2 emissions haven't changed much. If they were installed after 1993, we'd actually expect NO2 emissions to be reduced even more than emissions outside of the capital.

As you can see, messing around with answer choices can lead to further complications. Luckily, to be really good at GMAT CR, you don't need to go down that rabbit hole.

I hope that helps!
User avatar
Ishaan30
Joined: 25 Apr 2023
Last visit: 17 Nov 2025
Posts: 24
Own Kudos:
Given Kudos: 60
Location: India
Concentration: Entrepreneurship, General Management
GPA: 3.87
WE:General Management (Manufacturing)
Posts: 24
Kudos: 7
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Quote:
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.
Quote:
Yet although the proportion of new cars in Donia's capital city has always been comparatively high
I had a question regarding the statement underlined above. Is the proportion of new cars in the capital city high compared to the new cars in the other cities? Or is the proportion of the new cars in the capital city high compared to the old cars in the capital city?

I found the language a bit ambiguous here because the interpretation went in two different directions and therefore, eliminating (A) was difficult.
User avatar
GMATNinja
User avatar
GMAT Club Verbal Expert
Joined: 13 Aug 2009
Last visit: 19 Nov 2025
Posts: 7,443
Own Kudos:
Given Kudos: 2,060
Status: GMAT/GRE/LSAT tutors
Location: United States (CO)
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Products:
Expert
Expert reply
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Posts: 7,443
Kudos: 69,786
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Ishaan30
Quote:
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.
Quote:
Yet although the proportion of new cars in Donia's capital city has always been comparatively high
I had a question regarding the statement underlined above. Is the proportion of new cars in the capital city high compared to the new cars in the other cities? Or is the proportion of the new cars in the capital city high compared to the old cars in the capital city?

I found the language a bit ambiguous here because the interpretation went in two different directions and therefore, eliminating (A) was difficult.
It doesn't really matter, because, either way, we know that nitrogen dioxide (N2O) emissions have been significantly reduced throughout most of the country. So if the capital city has a higher proportion of new cars compared to the rest of the country, then we would certainly expect a decrease in N2O emissions in the capital. Likewise, if the capital simply has more new cars than old cars, then we would still be left wondering why N2O emissions have not significantly decreased.

That said, choice (A) contradicts the second interpretation above, so let's go with the first (which makes sense based on the word "comparatively"). In that case, maybe 45% of the cars in the capital city are new while only 30% of the cars in the rest of the country are new. Having catalytic converters in 30% of the cars could certainly explain the significant reduction in N2O in the rest of the country, so we're still left wondering why the capital city hasn't seen similar results.

(A) doesn't explain the discrepancy, so we can eliminate it.
   1   2 
Moderators:
GMAT Club Verbal Expert
7443 posts
GMAT Club Verbal Expert
231 posts
189 posts