In the mid-1970s, since birds were overcome by pollution, and routinel

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that in the 1970s, birds were overcome by pollution and routinely fell from the sky above Los Angeles freeways, and as a result officials in California were prompted to devise a plan to reduce automobile emissions.

Concepts tested here: Meaning + Pronouns + Verb Forms + Tenses + Awkwardness/Redundancy

• The past perfect tense (marked by the use of the helping verb "had") is used when a sentence contains two actions in the past; the helping verb "had" is used with the action in the "greater past".
• The simple past tense is used to refer to actions that concluded in the past.
• The simple past continuous tense is used to refer to actions that were ongoing over a period of time in the past.

A: This answer choice alters the meaning of the sentence through the phrase "plan that reduced"; the construction of this phrase incorrectly implies that the plan itself reduced automobile emissions; the intended meaning is that the plan was devised in order to reduce automobile emissions. Further, Option A suffers from a pronoun error, as the pronoun "this" lacks a clear and logical referent. Additionally, Option A incorrectly uses the simple past continuous tense verb "were...falling" to refer to an action that concluded in the past; remember, the simple past tense is used to refer to actions that concluded in the past, and the simple past continuous tense is used to refer to actions that were ongoing over a period of time in the past. Besides, Option A redundantly uses "since" alongside "prompted", rendering it awkward and needlessly wordy; this usage is redundant, as both convey a cause-effect relationship.

B: This answer choice alters the meaning of the sentence through the phrase "plan that would reduce"; the construction of this phrase incorrectly implies that the plan itself reduced automobile emissions; the intended meaning is that the plan was devised in order to reduce automobile emissions. Further, Option B suffers from a pronoun error, as the pronoun "it" lacks a clear and logical referent. Additionally, Option A incorrectly uses the past perfect tense verb "had been overcome" to refer to one of two actions that took place at the same time - the birds being overcome by pollution and the birds falling from the sky - remember, the past perfect tense (marked by the use of helping verb "had") is used when a sentence contains two actions in the past; the helping verb "had" is used with the action in the "greater past". Besides, Option B redundantly uses "since" alongside "prompted", rendering it awkward and needlessly wordy; this usage is redundant, as both convey a cause-effect relationship.

C: This answer choice alters the meaning of the sentence through the phrase "plan that reduced"; the construction of this phrase incorrectly implies that the plan itself reduced automobile emissions; the intended meaning is that the plan was devised in order to reduce automobile emissions. Further, Option C incorrectly uses the past perfect tense verb "had been overcome" to refer to one of two actions that took place at the same time - the birds being overcome by pollution and the birds falling from the sky - remember, the past perfect tense (marked by the use of helping verb "had") is used when a sentence contains two actions in the past; the helping verb "had" is used with the action in the "greater past".

D: Correct.This answer choice uses the phrase "prompting officials in California to devise a plan to reduce"; the construction of this phrase conveys the intended meaning - that the fact that birds were overcome by pollution and routinely fell from the sky above Los Angeles freeways prompted officials in California to devise a plan in order to reduce automobile emissions. Further, Option D avoids the pronoun errors seen in Options A and B, as it employs no pronouns. Additionally, Option D correctly uses the simple past tense verbs "fell" and the past participle "overcome" to refer to two actions that concluded in the past and took place at the same time - the birds being overcome by pollution and the birds falling from the sky. Besides, Option D is free of any awkwardness or redundancy.

E: This answer choice alters the meaning of the sentence through the clause "birds...were prompting"; the construction of this clause illogically implies that the birds that were overcome by pollution and routinely falling from the sky above Los Angeles freeways prompted officials in California to devise a plan to reduce automobile emissions; the intended meaning is that the fact that birds were overcome by pollution and routinely fell from the sky above Los Angeles freeways prompted officials in California to devise a plan to reduce automobile emissions.

Hence, D is the best answer choice.

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



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



All the best!
Experts' Global Team

A. since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced - awkward - were, falling reduced
B. since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it prompted officials in California to devise a plan that would reduce
C. birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced -- had been - going on action, reduced is past - so wrong
D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce
E. birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce--- were prompting - is wrong since birds dint prompt the officials

So we are left with D

The best way is to eliminate the choices that have "falling". So A, B and E are OUT.

C and D are left.

C. birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced ----> Had overcome the usage is wrong. You use past perfect to sequence the events not for stating parallel things "and" denotes parallelism.

D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce --------> D uses past tense - "fell"

In the mid-1970’s, since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.

A.since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways,this prompted officials in California to devise a plan that reduced
B. since birdsthat had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it promptedofficials in California to devise a plan that would reduce
C. birds had been overcomeby pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced
D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce ...CORRECT...
E. birds overcome by pollution and routinely fallingfrom the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce

In the mid-1970’s, since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.

A. since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced


this is incorrect. This should be used as a possessive adjective only and not as a pronoun replacing a noun. Also, it is trying to replace a verb (falling).
Also, plan to is the correct idiom in this case (should avoid plan to only if the sentence was like 'to plan to something').



B. since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it prompted officials in California to devise a plan that would reduce


it is incorrect. Pronouns cannot replace verbs. Plan to, same as A


C. birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced


Again, plan to. Also, all birds were overcome by pollution? This alternative has a meaning problem


D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce


overcome modifies birds, no meaning problem. The -ing modifier starting with prompting correctly modifies the preceding clause, making it clear that the falling of the birds prompted the officials. Plan to is correct.


E. birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce


This alternative sounds funny, birds were prompting officials? Also, and is wrong here because there is nothing else happening to birds overcome by pollution

Because of the very vastness of grammar, I have always found the elimination method to get correct answer in SC.

I will try to reason it via "Process of Elimination" :

(A) since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced - Different verb tense- parallelism error

(B) since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, it prompted officials in California to devise a plan that would reduce - Same as A. Unparallel and differnt verb tense

(C) birds had been overcome by pollution and routinelyfell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced - Same as A and B- Unparallel. First verb is past perfect and second one is present tense.

(D) birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce -Though this is awkward sounding but i dont see any error grammatically, so at this moment will leave it.Also it fixes the earlier error.

(E) birds overcome by pollution and routinely falling from the sky above Los Angeles freeways were prompting officials in California to devise a plan to reduce - Unparallel again. So eliminated.

Now we can see, we are left with only option D. Though its really awkward, specially because of the use of modifier "prompting. But still i will choose D as others have clear errors.
HENCE D.

Hey Shraddha,

Is it a rule that demonstrative pronoun "this" must be followed by a noun? Can you put some light on this concept?

Hello pikolo2510,

Thank you for your query.

Yes, on GMAT SC, it is a rule that demonstrative pronouns must be followed by the noun they refer to.

For example:

I found an old pen in the attic; this belonged to my great grandfather. ---> Incorrect because this is not followed by the noun.

I found an old pen in the attic; this pen belonged to my great grandfather. ---> Correct because this is followed pen, the noun it is meant to refer to.


This is all we need to know about demonstrative pronouns to solve GMAT SC problems correctly.


Hope this helps.
Thanks.
Shraddha

sayantanc2k , egmat

Doesn't option D gives a feeling that birds prompted officials to devise a plan. I am a little confused on this

Hi Prateek, that actually is the intended meaning as well. More specifically, an action of the birds (the falling of birds from the sky) prompted officials to devise a plan.

This is a classical usage of present participial phrase (prompting officials in California to devise a plan) that depicts a cause (the falling of birds) and an effect (officials devising a plan).

p.s. Our book EducationAisle Sentence Correction Nirvana discusses Participial phrases, their application and examples in significant detail. If someone is interested, PM me your email-id; I can mail the corresponding section.

I thought that verb-ing modifiers that come after a clause and are separated by a comma, can only describe the preceding action if both the verb-ing modifier and the actual action refer to the same object! In other words: they must have the same "doer".

Obviously, birds cannot prompt people to do sth, so the use of verb-ing modifier and thus option (D) must be wrong here.

GMATNinja egmat or anyone else please help..

This question is based on Construction.

Option A contains a redundant pronoun ‘this’. A pronoun refers to a noun, not an entire clause and the pronoun ‘this’ is intended to refer to the entire clause in this sentence. There is also a lack of parallelism between ‘were overcome’ and ‘falling’. So, Option A can be eliminated.

Option B also has a redundant pronoun ‘it’. A subordinate clause beginning with the conjunction ‘since’ is an adverbial clause providing a reason for whatever is stated in the main clause that follows. So, there is no need for a pronoun that refers to the reason. A pronoun doesn’t refer to a clause in any case. So, Option B can also be eliminated.

The past perfect tense ‘had been overcome’ is incorrect in this sentence as the sentence mentions a specific time – In the mid 1970’s. The simple past tense is used in such cases. There is also a lack of parallelism between the verbs ‘had been overcome’ and ‘fell’. So, Option C can be eliminated.

In Option E, the use of the past continuous tense ‘were prompting’ conveys the meaning that it was a continuous action. The subject of the verb would be ‘birds’, implying that birds were prompting officials. Since the meaning is illogical, Option E can be eliminated.

Option D has the appropriate construction and conveys the intended meaning that in the 1970’s, the phenomenon of birds overcome by pollution and routinely falling prompted officials to devise a plan to reduce automobile emissions.
Therefore, D is the most appropriate option.

Jayanthi Kumar.

can you please explain why promting is right? birds aren't prompting but comma verb-ing needs to have the same doer? Shraddha egmat

Hello arjsrivastav,

Wish you a Very Happy 2021.

Thank you for the question.

There are two conditions for the correct usage of the comma + verb-ing modifier that modifies an action in the preceding clause.

First condition: The comma + verb-ing modifier MUST modify the action in the preceding clause logically.

Second condition: The comma + verb-ing modifier MUST logically connect with the subject/doer of the modified action while presenting the logical modification.


Now. let's analyze the use of the comma + verb-ing modifier prompting officials in California... in the correct answer Choice D. It is clear from the context of the sentence that there is a cause-and-effect mentioned in this sentence.

Cause: Birds overcome by pollution started falling from the sky.

Effect: The official in California devised a plan to reduce automobile emissions.


In other words, we can say that because the birds started falling from the sky, their action prompted the officials to do something about the situation. If the birds would not have fallen from the sky, the officials would not have done anything. So the action done by the birds led to the action of the officials. Hence, the usage of the comma + verb-ing modifier is grammatical and logical.


Hope this helps.
Thanks.
Shraddha

In the mid-1970’s, since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced automobile emissions.


(A1) since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that WOULD reduce

(B1) since birds that had been overcome by pollution were routinely falling from the sky above Los Angeles freeways, promoting officials in California to devise a plan that would reduce
(B2) since birds that had been overcome by pollution routinely FELL from the sky above Los Angeles freeways, promoting officials in California to devise a plan that would reduce

(D1) birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce
(D2) birds overcome by pollution routinely AND fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce


A small confusion:

In D why we don't have " and " if overcome and fell are parallel verbs happening at same time.- D2 option is D2 correct option?
If they are not happening at same time, would "had overcome" not better than "fell"? B2 and B1 and A1 option - All options - A1,B1 and B2 can be correct?

Please share your thoughts. AndrewN

Good question, mSKR, but in this case, grammar alone can help us sort out the confusion. In (D), overcome is not a verb, but a modifier, one that acts as an adjective. You can tell because of the additional information, by pollution, that follows. These were birds that were overcome by pollution. Since we do not have a helping verb (in the form of to be) ahead of overcome, we know we are dealing with a modifier. The action, meanwhile, is fell. Birds fell is the clause. Note that for the apparent verbs to be parallel, we would also expect overcome to be overcame: birds overcame [some obstacle]. Of course, if birds overcame an obstacle, we would not expect them to have fallen from the sky, now would we?

As for the earlier options, as soon as I saw since, I put the brakes on those sentences. Why? Because the introductory phrase should set up an answer to the question, What happened in the mid-1970's? That is, I want to know what happened, a noun, not an explanation in since that further delays the answer to my question. I jumped straight down to (C), (D), and (E), and it did not take long for me to tease out (D) as the option with the fewest flaws.

I know it can be tempting to tinker with the answer choices, to explore what could be true in a different set of circumstances, but I would urge you to stick with what is presented, since GMAC™ has carefully crafted the question to be just as is, and we can only speculate as to what could be better or worse in other variants.

- Andrew

Is "overcome" correct in this sentence, describing something of past?