Carbon monoxide

[bravotalks]

Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.

(A) Carbon monoxide levels in the atmosphere grew by enough of an increased percentage during the twentieth century that it began to trap heat radiating from the Earth, and it caused the average surface temperature to rise.
(B) Carbon monoxide levels in the atmosphere increased by enough of a percentage during the twentieth century that they began to trap heat radiating from the Earth, causing the average surface temperature to rise.
(C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.
(D) Atmospheric carbon monoxide levels increased by a sufficient percentage during the twentieth century to begin trapping heat radiating from the Earth, which caused the average surface temperature to rise.
(E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.

OA is C

[bravotalks]

I understand the answer is C

But my question is [spoiler]in C, "to begin trapping" indicates that Levels of carbon monoxide increased only to begin trapping, but I would assume that the level of increased and as a result it started trapping. Is the meaning not changed here? Please explain. [/spoiler]

Question Source: Manhattan

[houstonrockets16]

Sorry I can't answer this question, but I know that
A and B used 'it' and 'they' without a reference.

And D and Ehave misplaced modifiers.

Sorry I can't help your question though

[raunekk]

i dont think there is a change in the meaning...

because the second clause modifies the first and also the meaning of the first clause concurs with the second..

[sjd00d]

What's wrong with E?

[jeevan.Gk]

YEP.. mE 2 same question.. wats wrong with E !

[hitmewithgmat]

(C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.
(E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.

Why E is incorrect.....

E is wordy. Let's take a look at the two.

Levels of atmospheric CO
Levels of CO in the atsmophere......
GMAT prefers a shorter, succinct one.

one more thing to add,
"increased" needs to come right after "subject" to describe. "during the twentieth century" interrupts this.

[sjd00d]

(C) Levels of atmospheric carbon monoxide increased sufficiently during the twentieth century to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.
(E) Levels of carbon monoxide in the atmosphere during the twentieth century increased enough to begin trapping heat radiating from the Earth, causing the average surface temperature to rise.

Why E is incorrect.....

E is wordy. Let's take a look at the two.

Levels of atmospheric CO
Levels of CO in the atsmophere......
GMAT prefers a shorter, succinct one.

one more thing to add,
"increased" needs to come right after "subject" to describe. "during the twentieth century" interrupts this.

Agree that E is wordy but totally disagree that C is the right choice. C is incorrect, "atmospheric" is an adjective that modifies CO, it implies that atmospheric CO is some special type of CO which is not the case.

[bravotalks]

sjd00d, not sure abt the adjective. After you mentioned even I am doubtful abt that answer. However, according to Manhattan, (C) is the correct answer.


And here is their reason for Choice (E).

(E) This choice alters the position of "during the twentieth century", thereby changing the meaning of the sentence. In this choice "during the twentieth century" modifies the carbon monoxide levels instead of describing when those levels "increased." This distorts the meaning by leaving open the possibility that carbon monoxide levels "increased enough" during some other time period (e.g., the 21st century).

[Alara533]

I understand the answer is C

But my question is in C, "to begin trapping" indicates that Levels of carbon monoxide increased only to begin trapping, but I would assume that the level of increased and as a result it started trapping. Is the meaning not changed here? Please explain.
Question Source: Manhattan

C says, monoxide increased sufficiently to begin trapping. (Not that monoxide increased only to begin trapping).

I think that makes it C. But at first, I felt E was correct.