A successful ascent of Mt. Everest is rendered tremendously difficult

Question

A successful ascent of Mt. Everest is rendered tremendously difficult by numerous obstacles, not the least of which  is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes.

(A) is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes

(B) are the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes

(C) is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterizes very high altitudes

(D) are the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterizes very high altitudes

(E) is the challenges of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes

Both the decreased atmospheric pressure and the low oxygen availability are things to which the climber must adjust, and the sentence needs to express that one obstacle is the challenge of adjusting to both of these things.

Since this predicate nominative (essentially, Y in the sentence X is Y) is singular, we need "is," not "are," so B and D are out.

(E) is out because "is the challenges" doesn't work.

Finally, both the decreased atmospheric pressure and the low oxygen availability characterize very high altitudes; since the verb has a plural subject, (C) is out (we couldn't say "they characterizes").

(A) is the only answer choice in which all subjects agree with all verbs.

rockstar23 · Accepted Answer

A) is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes
  Correct    is  correctly agrees with  the challenge  and  characterize  agrees with  altitudes

B) are the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes
Use of  are  is incorrect. Hence incorrect

C) is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterizes very high altitudes
 characterizes  does not agree with  altitudes . Hence incorrect

D) are the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterizes very high altitudes
use of  are  and  characterizes  introuduces S-V errors. Hence incorrect

E) is the challenges of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes
Here  challenges  is plural so use of  is  is incorrect. Hence incorrect

ExpertsGlobal5 · Answer

Dear Friends,

Here is a detailed explanation to this question-

Choice A:  Option A maintains proper subject-verb agreement throughout the sentence. Thus, Option A is correct.

Choice B:  In Option B, we see a clear subject-verb disagreement between "are" and "challenge". Remember, although there are two elements of this challenge mentioned, the adjustment and low oxygen availability, the challenge in question is a singular combination of both. Thus, Option B is incorrect.

Choice C:  In Option C, we see a subject-verb disagreement between "characterizes" and "the decreased atmospheric pressure and correspondingly low oxygen availability". Remember, when connected by an "and", singular nouns become plural. Thus, Option C is incorrect.

Choice D:  Option D features the same subject-verb disagreement that Option B does. Thus, Option D is incorrect.

Choice E:  In Option E, we see a clear subject-verb disagreement between "is" and "challenges". Thus, Option E is incorrect.

Hence, A is the best answer choice.

To understand the concept of "And v/s other conjunctions on GMAT”, you may want to watch the following video (~1 minute):

https://www.youtube.com/watch?v=oLAjw4aR0rM

All the best!
Experts' Global Team

cssk · Answer

A successful ascent of Mt. Everest is rendered tremendously difficult by numerous obstacles, not the least of which is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes.

A)  is  the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that  characterize  very high altitudes Yes. Proper SV agreement. Hold it for a while. 
B)  are  the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes Wrong SV pair. 
C) is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that  characterizes  very high altitudes decreased atmospheric pressure and correspondingly low oxygen availability together characterized very high altitudes but neither of the both alone. 
D)  are  the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that  characterizes  very high altitudes Wrong SV pair again. 
E) is the  challenges  of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes is the challanges is wrong.

Now +A it is.

Hope that helps.

jlgdr · Answer

First split IS vs ARE. Is here refers to the least of which, singular Second split the challenge singular not plural Third split A and B characterize cause its a compound subject we need plural Hence A Hope it helps Cheers! J

mdacosta · Answer

can someone elaborate on why IS is correct instead of ARE? Is it because "not the least of which" denotes a singular item? I got it right just sorta being a native speaker, but otherwise i'm confused. thanks!

godot53 · Answer

Its an inverted construction, where "challenge/challenges" is the keyword that determine "is/are". Refer this : https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2016/1 ... tructures/

nks2611 · Answer

hi,
 thanks for the link . 
well could you please help me out about my understanding on this problem , here it is-

in answer A , is followed =challenge(subject)
 characterize= atmospheric pressure and correspondingly low oxygen(2nd plural subject)

please correct me if i am wrong . i really appreciate that.

thanks

godot53 · Answer

Yes, your understanding is correct. But, technically, "challenge" is not the subject. Consider this.. There are books on the table. There is a book on the table. Here, "there" is actually an expletive, or the logical subject, and the "books/book" is the object. Since, both the following sentences are derived from... Book/books are/is on the table: its "book/books" that decide which verb to use. Again, I would argue "that" is the subject of the relative clause "that characterize very high altitudes" and "that" refers to a compound noun, hence a need for plural verb. So, I won't use the term subject for "atmospheric pressure and correspondingly low oxygen", because "that" is the subject here. ---- However, by whatever name you define all the above, as long as you realize the need for plural verb and eliminate the answer choices, you are done. All you need is to recognize the splits - "characterizes/characterize" and "is/are". Cheers !! :-D

nks2611 · Answer

Thanks for the emphatic explanation.  , but i didn't get how did you recognize the subject of 2nd part, ('that' is a compund noun) i didn't get this part. 
Could you please elaborate more . 
Loads of kudos for the great explanation ?

Sent from my vivo 1601 using  GMAT Club Forum mobile app

godot53 · Answer

Thank you !!

"that" is not a compound noun. What I mean :
1. "that" refers to a compound noun i.e. "atmospheric pressure and correspondingly low oxygen", hence a need of plural verb form "characterize".
2. "that" itself is the subject and not the compound noun "atmospheric pressure and correspondingly low oxygen".

kivalo · Answer

I think that this is a really good question. It has two splits where you have to decide based on meaning (is vs. are and characterize vs characterizes), and also tests for parallelism.
The key is to really think what the original sentence tries to say:

A successful ascent of Mt. Everest is rendered tremendously difficult by numerous obstacles, not the least of which is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes.

As per my understanding: Is verb for challenge and Characterize for plural subject ,i.e decreased atmospheric pressure and correspondingly low oxygen availability

-The challenge is an example of  one  obstacle. If we were given two examples of  numerous obstacles , we would have to use  are .
-When we decide whether it is characterize or characterizes we have to ask what is the subject. Is it 'correspondingly low oxygen availability' or 'the decreased atmospheric pressure and correspondingly low oxygen availability'? It is logiccal that both of them characterize very high altitudes, hence plural verb is needed.

GMATGuruNY · Answer

OA:  A successful ascent is rendered difficult by numerous obstacles, not the least of which  is  the challenge of adjusting to the atmospheric pressure. 
Here, SOMETHING is not the least of numerous obstacles that render a successful ascent difficult.
What is that something?
 The CHALLENGE of adjusting to the atmospheric pressure. 
Conveyed meaning:
 The CHALLENGE of adjusting to the atmospheric pressure IS not the least of numerous obstacles that render a successful ascent difficult. 
In the OA, the verb in green is singular to agree with  the challenge .

globaldesi · Answer

characterizes should modify "low oxygen availability" . 
So as per SVA "C" is a better choice.
Can someone help resolve this query?

GMATGuruNY · Answer

OA:  the...pressure and...availability that characterize very high altitudes 
Here,  characterize  (plural) agrees with  the pressure and availability  (plural).

Wulfang · Answer

How is 'is' correct when there are clearly 2 obstacles metioned: adjusting to low pressure AND adjusting to low oxygen availability? Even the word 'and' is mentioned, so why are we associating the verb to the first element only?

MartyTargetTestPrep · Answer

The verb "is" does not go with "the decreased atmospheric pressure and correspondingly low oxygen availability."

"Is" goes with "the challenge of adjusting ...," which is singular.

Deadpool3 · Answer

Hi  AjiteshArun  ,  GMATNinja  ,  MagooshExpert  ,  GMATGuruNY  ,  VeritasPrepBrian  ,  MartyTargetTestPrep  ,  DmitryFarber  ,  VeritasKarishma  ,  generis

Could "the challenge" refer to "that", which could have the verb "characterize s "?

A successful ascent of Mt. Everest is rendered tremendously difficult by numerous obstacles, not the least of which is  the challenge  of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability  that   characterize very high altitudes.

GMATGuruNY · Answer

No.

Proposed revision:
 the challenge of adjusting to the decreased atmospheric pressure and  correspondingly low oxygen availability that characterizes very high altitudes  .
Here, the subject for  characterizes  (singular) seems to be  availability  -- the nearest preceding singular noun -- since it is logical to convey that LOW OXYGEN AVAILABILITY characterizes very high altitudes.

If the intended subject for  characterizes  is  challenge , we could make this intention clear as follows:
 the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability -- a challenge that characterizes very high altitudes.

amitahlawat06 · Answer

A successful ascent of Mt. Everest is rendered tremendously difficult by numerous obstacles, not the least of which is the challenge of adjusting to the decreased atmospheric pressure and correspondingly low oxygen availability that characterize very high altitudes.

As per my understanding: Is verb for challenge and Characterize for plural subject ,i.e decreased atmospheric pressure and correspondingly low oxygen availability

A successful ascent of Mt. Everest is rendered tremendously difficult

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GMAT Sentence Correction (SC - EA only) Questions

A successful ascent of Mt. Everest is rendered tremendously difficult

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