The success of the program to eradicate smallpox has stimulated experts to pursue what they had not previously considered possible−better control, if not eradication, of the other infections such as measles and yaws. (A) what they had not previously considered possible−better control, if not eradication, of the other infections such as (B) what they had not previously considered a possibility−better control, if not eradication, of such infections like (C) something they had not previously considered possible−better control, if not eradication, of such infections as (D) something not considered a previous possibility−better control and perhaps eradication, of other infections such as (E) the possibility of what they had not previously considered possible−better control and possibly eradication of infections like https://www.nytimes.com/1979/10/16/archives/the-doctors-world-the-eradication-of-smallpox.html It has boosted interest in the global aspects of medicine by pointing up how relatively simple measures could help suppress many infections in the third world that the developed countries controlled long ago. Eradication of smallpox has stimulated experts to debate what they had not previously considered possible — better control, if not eradication, of other infections such as measles, yaws and common childhood diseases.

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The success of the program to eradicate smallpox has stimulated expert

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Fdambro294

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21 Sep 2022, 01:26

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Great explanation!

It’s not necessary to have an explicit “past tense” reference in the sentence. All that is required is a past time frame or event on which the past perfect action has bearing.

That being said, the action of “has stimulated” is a completed event that occurred in the past. The fact that it is relevant to the current time frame is the reason why we use the present perfect verb tense. However, both the success of the program and the “stimulating” action are events that occurred in the past.

So, as pointed out, this is not really a violation of “the rule.”

EducationAisle

dabaobao

Is "they had not previously considered possible" using past perfect? If so, is it not violating a grammar rule since we don't have 2 events in past?

Hi dabaobao, this is definitely past perfect and it is not a violation of the rule.

Following two events happened in the past:
(i) stimulated experts to pursue <something>
(ii) earlier, they had not previously considered <something> possible

Clearly, (ii) happened before (i) and hence, is expressed as past perfect.

For example, following would also be a correct sentence:

Peter has finally aced the exam that he had earlier not been able to ace.

Again, ace the exam and not able to ace earlier, are two events that happened in the past. The event that happened earlier (not able to ace earlier) is expressed as past perfect.

Apart from the sentence under consideration, there are other official examples of this nature as well:

The success of the program to eradicate smallpox has stimulated experts to pursue something they had not previously considered possible -- better control, if not eradication, of such infections as measles and yaws.

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AdiM07

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05 Oct 2022, 05:23

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ChrisLele

The success of the program to eradicate smallpox has stimulated experts to pursue what they had not previously considered possible - better control, if not eradication, of the other infections such as measles and yaws.

d) something they had previously thought impossible - better prevention, if not eradication, of

By omitting the 'such...as' the meaning of the sentence changes. No the sentence focuses only on measles and yaws. The 'such as' broadens the scope of infections.

Option (D) does retain the "such as" in the question above.
Accordingly, it's also seems like an apposite contender for the correct answer. Can you please elaborate on the choice again?

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07 Oct 2022, 20:55

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AdiM07

ChrisLele

Option (D) does retain the "such as" in the question above.
Accordingly, it's also seems like an apposite contender for the correct answer. Can you please elaborate on the choice again?

We attempted to explain why (C) is better than (D) in this post: https://gmatclub.com/forum/the-success- ... l#p2756856. If that doesn't help, let us know, and we'll do our best to clarify.

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09 Dec 2022, 06:29

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GMATNinja

AdiM07

ChrisLele

Option (D) does retain the "such as" in the question above.
Accordingly, it's also seems like an apposite contender for the correct answer. Can you please elaborate on the choice again?

We attempted to explain why (C) is better than (D) in this post: https://gmatclub.com/forum/the-success- ... l#p2756856. If that doesn't help, let us know, and we'll do our best to clarify.

Hey Charles GMATNinja, having hard time understanding the past perfect on this sentence. I discarded option C and all options with "had"/past perfect as I could not find a time market, I was having hard time to understand the sequence using the past perfect. Also, saw many problems with Present Perfect and Past Perfect combo to be identified as "Wrong". Can you provide some clarity on the usage of Past Perfect in this question? Thanks!

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09 Dec 2022, 22:07

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Although I got this one correct, i am not sure about the use of past perfect tense in option C. We have "previous" so i believe, using past perfect is not ideal here.
Please share your valuable insight here.
Thanks

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29 Jun 2023, 06:17

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In all these options. Doesn't the marker 'previously' make the term 'had' redundant?. I got this in my mock when I wasn't left with much time so I went with 'D'. 'B' & 'E' were anyways out cause of the word 'like'.

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29 Jun 2023, 12:16

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Prithvi08

In that vein, you could argue that any use of "previously" is redundant, because you'll always be writing about something in the past, and will therefore be using the past or past perfect tense. We could say the same for modifiers such as "also" or "actually," which don't really add much in the way of meaning. However, these modifiers can increase clarity by emphasizing the intended meaning. We use "previously" to emphasize a change: previously things were this way, and now/later on they are different.

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05 Oct 2023, 17:33

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The success of the program to eradicate smallpox has stimulated experts to pursue what they had not previously considered possible−better control, if not eradication, of the other infections such as measles and yaws.

Option elimination -

(A) what they had not previously considered possible−better control, if not eradication, of (correct usage - usage of what to introduce a relative clause to modify the noun experts) the other infections such as - the problem is "the" The means only limited to "the other infections." What are those specific other infections - measles and yaws?. The sentence actually means other infections such as measles, yaws bla bla ....

(B) what they had not previously considered a possibility−better control, if not eradication, of such infections like - easy one. Like is wrong.

(C) something they had not previously considered possible−better control, if not eradication, of such infections as - the is gone, even other is gone. Better.

(D) something not considered a previous possibility−better control and perhaps eradication, of other infections such as - "a" is a problem. "and" is a problem. The actual meaning is better control (if not eradication). Here it says: better control and eradication - either we control or eradicate ....how do we do control and eradication simultaneously? Wrong. Comma before "of" not required.

(E) the possibility of what they had not previously considered possible−better control and possibly eradication of infections like - same "and". Like is wrong.

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