In Scotland, the number of wild salmon have been reduced because of un

Question

In Scotland, the  number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting , by pollution, and by various other threats to the fish’s habitat.

A. number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting

B. number of wild salmon is reduced because deep-sea and coastal netting is not controlled

C. numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting

D. wild salmon’s numbers are reduced by deep-sea and coastal netting that is not controlled

E. wild salmon’s numbers have been reduced by uncontrolled deep-sea and coastal netting

N750 · Accepted Answer

I will go with E.
This agree with subject and follows parallel structure for the later part of the sentence.

 
 Subject agrees with verb and also rest of the sentence is parallel as all the reasons are starting by "by". 

 Good question.....

ExpertsGlobal5 · Answer

Dear Friends,

Here is a detailed explanation to this question-

Concepts tested here: Subject-Verb Agreement + Tenses + Parallelism + Awkwardness/Redundancy

• All elements in a list must be parallel.
• The present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present. 
• The simple present tense is used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.

A:  This answer choice fails to maintain parallelism among "because of uncontrolled...netting", "by pollution", and "by various other...habitat"; please remember, all elements in a list must be parallel. Further, Option A uses the needlessly wordy phrase "number of wild salmon", leading to awkwardness and redundancy.

B:  This answer choice incorrectly uses the simple present tense verb "is" to refer to an action that concluded in the past but continues to affect the present; please remember, the present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Further, Option B fails to maintain parallelism among "because... not controlled", "by pollution", and "by various other...habitat"; please remember, all elements in a list must be parallel. Additionally, Option B uses the needlessly wordy phrase "number of wild salmon", leading to awkwardness and redundancy.

C:   Correct.  This answer choice incorrectly refers to the plural noun "numbers" with the singular verb "has been". Further, Option C fails to maintain parallelism among "because of uncontrolled...netting", "by pollution", and "by various other...habitat"; please remember, all elements in a list must be parallel. Additionally, Option C uses the needlessly wordy phrase "numbers of wild salmon", leading to awkwardness and redundancy.

D:  This answer choice incorrectly uses the simple present tense verb "are" to refer to an action that concluded in the past but continues to affect the present; please remember, the present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Additionally, Option D uses the needlessly wordy phrase "that is not controlled", leading to awkwardness and redundancy.

E:  This answer choice correctly refers to the plural noun "numbers" with the plural verb "have been". Further, Option E correctly uses the present perfect tense verb "have been" to refer to an action that concluded in the past but continues to affect the present. Additionally, Option E maintains parallelism among "by...netting", "by pollution", and "by various other...habitat". Besides, Option E is free of any awkwardness to redundancy.

Hence, E is the best answer choice.

To understand the concept of "Simple Tenses" on GMAT, you may want to watch the following video (~1 minute):

https://www.youtube.com/watch?v=eZj-SubJwsM

To understand the concept of "Present Perfect Tense" on GMAT, you may want to watch the following video (~2 minutes):

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

All the best!
Experts' Global Team

Ravshonbek · Answer

It is pretty confusing for me, But will stick to C 

 ...the number of ...  is singular. 
but as for the paralellism in here: ...because of...by...by... have no reasoning.

wild salmon's  numbers --a bit not sure about this in D --- it is like a fish assigned a number and it is reduced. let's say the fish numbered and the numbers changed.

I think NUMBERS in here doesnt convey the menaing of QUANTITY. 

any better ideas?

Ravshonbek · Answer

In Scotland, the number of wild salmon have been reduced because of uncontrolled deepsea and costal netting, by pollution, and by various other threats to the fish's habitat.

(A) number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting

(B) number of wild salmon is reduced because deep-sea and coastal netting is not controlled

(C) numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting

(D) wild salmon's numbers are reduced by deep-sea and coastal netting that is not controlled

(E) wild salmon's numbers have been reduced by uncontrolled deep-sea and coastal netting

My doubt

Dont we need 'is'/'has' with The number since the number is singular? I understand that although E is parallel it is also plural... So how come E is correct still?

C lags parallelism but is singular...

Please help me with my confusion

fatihaysu · Answer

Actually it is kind of easy

A- The number of wild solman HAVE--not correct
B- Deep sea and coastal netting IS---not correct
C- the NUMBERS- not correct
D- same reason with B
E- it is the correct one

you can do it in 20 sec

sudhir18n · Answer

Clean E.
You are right that 'the number of' needs 'singular' but if you see , E changes that structure.
'Wild Salmon's numbers' = plural , hence 'have'
 E also maintains ||sm reduced by'A and B', by C , and by D.

siddhans · Answer

When is the usage of possessibe nouns correct in GMAT like in case of E? I sometimes eliminate choices if I see possessive nouns...

parker · Answer

siddans, the confusion might come from a few different phrases that look very similar:

"the number of" takes a singular verb
"a number of" takes a plural verb
"numbers" will take a plural verb

This knocks off A and C. A big difference between B, D, and E is that E uses the present perfect (which neatly indicates that the action we're talking about here-- the reduction of the wild salmon's numbers--is a complete action in the past, and that we currently still feel the effects of that action in the present). B and D also violate parallelism, as mentioned above, so E is the only choice left standing.

OP, was "the" non-underlined? That seems important, because the inclusion of the definite article in the phrase "the wild salmon's" makes it crystal clear that we are talking in the abstract--"the wild salmon" as a SPECIES is what has had its numbers reduced.

ankurgupta03 · Answer

In Scotland, the number of wild salmon have been reduced because of uncontrolled deepsea and coastal netting, by pollution, and by various other threats to the fish’s habitat.

A. number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting 
 Wrong, should be number has been reduced, Parallelism missing 
B. number of wild salmon is reduced because deep-sea and coastal netting is not controlled 
 Wrong, Parallelism missing 
C. numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting 
 Wrong, should be numbers of wild salmon have been reduced, Parallelism missing 
D. wild salmon’s numbers are reduced by deep-sea and coastal netting that is not controlled 
 Wrong, Should be have been reduced 
E. wild salmon’s numbers have been reduced by uncontrolled deep-sea and coastal netting
 Correct

Take Away:
Always pay attention to the item before the and in a list, and make every item parallel to that.
The number of - Singular,
A number of - plural

Heman105 · Answer

In Scotland, the  number of wild salmon have been reduced because of uncontrolled deepsea and coastal netting ,  by pollution, and by various other threats to the fish’s habitat.

Here, Parallelism needed : by x || by y || (and) by z

A.  number  of wild salmon  have  been reduced because of uncontrolled deep-sea and coastal netting -->  "i) the number - have" subject-verb number mismatch. require singular verb ii) parallelism error 
B. number of wild salmon is reduced  because  deep-sea and coastal netting is not controlled -->  because x || by y & by z - Not parallel 
C. numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting -->   i) "the numbers of x has" : subject-verb number mismatch. require plural verb ii) parallelism error 
D. wild salmon’s numbers are reduced  by deep-sea and coastal netting that is not controlled   -->  "deep-sea and coastal netting that is not controlled" not parallel to "by pollution, and by various other threats to the fish’s habitat" 
E. wild salmon’s numbers have been reduced  by uncontrolled deep-sea and coastal netting  -->  Correct - Parallel

Skywalker18 · Answer

In Scotland, the  number of wild salmon have been reduced because of uncontrolled deepsea and coastal netting , by pollution, and by various other threats to the fish’s habitat.

A. number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting - subject-verb agreement issue ; parallelism issue
B. number of wild salmon is reduced because deep-sea and coastal netting is not controlled - parallelism issue ; present tense is incorrect here 
C. numbers of wild salmon has been reduced because of uncontrolled deep-sea and coastal netting - subject-verb agreement issue
D. wild salmon’s numbers are reduced by deep-sea and coastal netting that is not controlled - parallelism issue ; present tense is incorrect here - "are reduced" is written in a tense that can NEVER be used for something like that (a single instance; an event)
E. wild salmon’s numbers have been reduced by uncontrolled deep-sea and coastal netting - Correct

Answer E

thangvietnam · Answer

gmat tests meaning ,and , so, we need to understand meaning.
"because" and " because of" are used to show a reason . "by" is used to show an agent making a previous action. inhere, we need to show an agent. we need "by" , not "because of' or "because".

the difference between present perfect and simple present and between present perfect and past perfect is the corner stone of tense system, a point gmat alway want to test us.

simple present shows a timeless fact or a condition which exist indefinitely, we think
present perfect show an action happen in a period from a point in past to present. action can be finished in the past or can continues until present. the difference is that present perfect show a period but simple present shows no period.

it takes a long time of using tenses to see the difference among them.

inhere, reducing need a period to be logic. reducing can not exist indefinitely. present simple is wrong in choice D. E is left.

dcummins · Answer

Check the parallelism marker in the non-underlined portion of the sentence. we need to carryover "by". This eliminate a few answers.

Hoozan · Answer

In Scotland,  the number of wild salmon have been reduced because of uncontrolled deep-sea and coastal netting , by pollution, and by various other threats to the fish’s habitat.

Meaning Analysis:  In Scotland the wild salmon population has reduced. The causes for this reduction are (1) Uncontrolled deep-sea and coastal netting (2) pollution and (3) other threats to the salmon fish's habitat.

Sentence Structure:  
In Scotland,  (Prepositional phrase modifying the following noun "the number") 
the number  (Singular subject) 
of wild salmon  ("wild salmon" is in a prepositional phrase hence not a subject) 
have been reduced  (plural verb to singular subject) 
because of  (contextual word indicating reason of some event) 
uncontrolled deep-sea and coastal netting  (element 1 of parallelism) 
, by pollution  (element 2 of parallelism) 
, and  (parallelism marker) 
by various other threats to the fish’s habitat.  (element 3 of parallelism)

We have a clear SV agreement error. The singular subject "number" is given a plural verb "have been". This error is a deterministic error.

Moreover, we see that the three elements are not parallel to each other. The last two elements in the non-underlined part are prepositional phrases beginning with "by" while the first element in the underlined part is a compound noun. "deep-sea and coastal netting" is a compound noun in which "uncontrolled" is a modifier modifying this noun entity.

"The number" is given a singular verb "is" thus rectifying the SV agreement error. However the parallelism error still exists. While the first element  "deep-sea and coastal netting is not controlled"  is a clause the other two elements are prepositional phrases.

We also notice a new SV agreement error out here. "deep-sea and coastal netting" is a compound noun and this "plural noun" is given a singular verb "is". This error is a deterministic error.

Notice the subject "numbers" is plural and so we need a plural verb "have been" BUT here we see a singular verb "has been" leading to a SV agreement error.

The parallelism error still exists. The first is element is a compound noun while the other two elements are prepositional phrases.

I can't really point out the grammar errors out here BUT surely this sentence is not well structured. "Numbers" surely is plural and hence the plural verb "are is correct" However, I am not happy with "Salmon's number". A much better way to say this is by stating "the number of Salmons"

In terms of parallelism, the first element is indeed a prepositional phrase "by deep-sea and coastal netting" thus making the structure of this element parallel to the structure of the other two elements. However, the modifier "that is not controlled" makes this structure inferior. A much better way to say this would be "uncontrolled deep-sea and coastal netting"

I believe it is alright to use simple present tense "are reduced" out here. Don't think that there is any meaning change out here.

Correct.  All SV errors and parallelism errors are rectified.

Correct Choice:  (E)

Learning:- 
1. A subject cannot lie in a prepositional phrase: Hence "wild salmon" is not the subject"
2. ",FANBOYS" can be used despite the absence of two ICs: Hence we see ",and" used as a parallelism marker between the three supposedly parallel elements.
3. A compound noun is a group of nouns connected by "and" thus making this entire noun entity plural: E.g. Hoozan   and   Ron   are eating  the cake. Though "Hoozan" and "Ron" are both singular, the connector "and" makes this a compound noun  (plural noun)

CrackverbalGMAT · Answer

This question is based on Subject-Verb agreement and Parallelism.

‘The number’  of anything is considered a singular subject. So, the plural verb ‘have’ does not agree with the subject in option A. 
There is also a lack of parallelism at the end of the sentence in this option - reduced  because of  uncontrolled deep-sea and coastal netting,  by  pollution, and  by  various other threats to the fish’s habitat. 
The sentence gives a list of causes of the reduction in the number of wild salmon. So, the various causes have to expressed in the same manner. However, in Option A, there is a lack of parallelism between the conjunction ‘because’ and the preposition ‘by’. So,  Option A  can be eliminated.

Option B changes the meaning of the sentence. The meaning conveyed by this option is that the number of wild salmon is reduced because deep sea and coastal netting is not controlled by pollution etc. So,  Option B  can also be eliminated.

Option C has a subject-verb disagreement. The singular verb ‘has’ does not agree with the plural subject ‘the numbers’. So,  Option C  can be eliminated.

Option D is wordy. The phrase “deep-sea and coastal netting that is not controlled” could be better phrased as “uncontrolled deep-sea and coastal netting”. Furthermore, since the sentence doesn’t give any other indication of what the appropriate tense of the sentence is, there is no reason to change the tense from what it is in the original sentence. The simple present tense “are reduced” is an unnecessary change from the present perfect tense. So,  Option D  can be eliminated.

The parallelism has been maintained in Option E - In Scotland, the wild salmon’s numbers  have been reduced by  uncontrolled deep-sea and coastal netting,  by  pollution,  and by  various other threats to the fish’s habitat. 
This option also maintains the present perfect tense that is used in the original sentence.
 Therefore, E is the most appropriate option.

Jayanthi Kumar.

kntombat · Answer

I will choose option E,
It agrees with the subject and follows a parallel structure for the later part of the sentence.

Praveenksinha · Answer

E is free from parallelism error along with correct tense.

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