Sentence Correction

Discussion of greenhouse effects has usually focused on whether the
Earth would warm and by how much, but climatologists have indicated all
along that the most obvious effects, and those that would have the largest
impact on people, would be extremes of temperature, precipitation,
and storminess.
A. the most obvious effects, and those that would have the largest
impact on people, would be extremes of temperature,
precipitation, and storminess
B. the effects that are the most obvious ones, extremes of temperature,
precipitation, and storminess, would be those impacting
the most on people
C. those effects to have the largest impact on people, extremes of
temperature, precipitation, and storminess, are what are the
most obvious effects
D. extremes of temperature, precipitation, and storminess, the most
obvious effects, that they would have the largest impact on people
E. extremes of temperature, precipitation, and storminess, which are
the most obvious effects, are those to impact the most on people

I have two questions about this one.
The first one is about "the", do I need to add it before discussion?
The the explanation on OG say the choice C "the phrase whether ... warmer and to what extent are parallel"?
Thank you in advance

SC23 in the OG16 appears as follows:

Discussion of greenhouse effects have usually had as a focus the possibility of Earth growing warmer and to what extent it might, but climatologists have indicated all along that precipitation, storminess, and temperature extremes are likely to have the greatest impact on people.

(A) Discussion of greenhouse effects have usually had as a focus the possibility of Earth growing warmer and to what extent it might,

(B) Discussion of greenhouse effects has usually had as its focus whether Earth would get warmer and what the extent would be,

(C) Discussion of greenhouse effects has usually focused on whether Earth would grow warmer and to what extent,

(D) The discussion of greenhouse effects have usually focused on the possibility of Earth getting warmer and to what extent it might,

(E) The discussion of greenhouse effects has usually focused on whether Earth would grow warmer and the extent that is,

In A and D, have (plural) does not agree with discussion (singular).
Eliminate A and D.

B: Discussion of greenhouse effects has usually had...whether Earth would get warmer.
This meaning is nonsensical.
Eliminate B.

In E, the extent that is does not convey a clear meaning.
The extent that is WHAT?
Eliminate E.

The correct answer is C.

The first one is about "the", do I need to add it before discussion?

As illustrated by the OA, discussion does NOT need to be preceded by the.
Do not worry about this issue.
The GMAT does not test whether a noun must be preceded by the.

the explanation on OG say the choice C "the phrase whether ... warmer and to what extent are parallel"?

OA: Discussion of greenhouse effects has usually focused on whether Earth would grow warmer and to what extent [Earth would grow warmer].
Here, the words in brackets are omitted, but their presence is understood.
The two portions in red are parallel in that each is a NOUN CLAUSE serving as an object of the preposition on.

Thank you very much and I also have a very quick question. How to understand the to in the to what extent

Crystal W wrote:Thank you very much and I also have a very quick question. How to understand the to in the to what extent

Rather than worry about the function of to on its own, focus on how the entire idiom is used.
to what extent functions the same way as how, why, when, where, etc.
Scientists are trying to determine HOW the planet has changed.
Scientists are trying to determine WHY the planet has changed.
Scientists are trying to determine TO WHAT EXTENT the planet has changed.

Get it! Thanks!

Mitch,

Thanks for your explanation for this SC questions. It's really helpful.

I have a basic question though- To what extent [Earth would grow warmer]. In this second half of the sentence the infinitive along with ellipsis- "To what extent Earth" serves as Noun?

noxy416 wrote:Mitch,

Thanks for your explanation for this SC questions. It's really helpful.

I have a basic question though- To what extent [Earth would grow warmer]. In this second half of the sentence the infinitive along with ellipsis- "To what extent Earth" serves as Noun?

OA: Discussion has usually focused on to what extent Earth would grow warmer.
Here, to what extent seems to serve as a conjunction, connecting the clause in red to the clause in blue.

Thanks Mitch