Please help me answering following SC from GMAT Prep Test 1:

Whereas the use of synthetic fertilizers has greatly expanded agricultural productivity in many parts of the world, an increase in their use can create serious environmental problems such as water pollution, and their substitution for more traditional fertilizers may accelerate soil structure deterioration and soil erosion.
A. an increase in their use can create serious environmental problems such as water pollution, and their substitution for more traditional fertilizers
B. an increase in their use can create serious environmental problems like water pollution, and if substituted for more traditional fertilizers, it
C. if these fertilizers are used increasingly, they can create serious environmental problems such as water pollution, and if used as substitutions for more traditional fertilizers, they
D. the increased usage of these fertilizers can create serious environmental problems such as water pollution, while if substituted for more traditional fertilizers, this substitution
E. the increased usage of these fertilizers can create serious environmental problems like water pollution, while their substitution for more traditional fertilizers

I did get an idea on how to start it but I may be completely wrong:
The word "whereas" in the beginning suggest that the use of fertilizers is to be contrasted.
But I was bit lost between D and E.
What is the difference between phrases:
"An increase in their use"
"the increased usage of "
Any help is appreciated!

is the answer E ?

I would say D is the correct answer.

I discard B and E because they use "like" instead of "such as".

I think "and if used as substitutions for" is not correct in C. And also I think that the use of "if these fertilizers are used increasingly" is awkward..

So I´m down to A or D.

I´m not sure how to choose here but I think I prefer D

What is the correct solution?

A bit of a red herring - you could technically construct the sentence correctly either way. I'd prefer the "an increase in their use" however because that emphasizes the distinction I'm trying to make - the key point is the increase, and this is emphasized by making "the increase" the subject. But I'd go look for other, more definitive grammar errors first before deciding on this.

Luci correctly points out a distinction between "such as" and "like" in the answers. Such as means "for example" - like means "similar to." (In everyday spoken language, people use "like" as the default now - but that's grammatically incorrect.) Eliminate B and E. (B also has a pronoun error - "it" refers to a plural noun.)

C messes up the contrast I want to make by starting with "if these fertilizers." Also generally kind of awkward / wordy, but only use that as a tiebreak.

The problem with D lies at the end of the choice: "while if substituted for more traditional fertilizers, this substitution..." Notice the first part of that, before the comma - it never actually mentions what is being substituted, either via a noun or pronoun. This is a modifying clause. The modifier is meant to modify "synthetic fertilizers" which is a noun, so this is a noun modifier - and noun modifiers must touch the noun they modify. But "this substitution" follows the comma, not "synthetic fertilizers" (or some other noun or pronoun that refers to synthetic fertilizers). No good. Eliminate D.

Which leaves us with A. Notice that A doesn't sound particularly good. But there's nothing grammatically wrong with it... It's not uncommon for A to sound not-so-good when it is the right answer - otherwise, how would they get someone to cross off A when it's right, especially on a hard question?

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

Stacey rocks!!

Thanks Stacey!
The OA is D.

Your answer is explanatory and logical.

Stacey said the OA is A???

I'm also debating between A and D, but lean toward D for two reasons:
1) A's use of "their" could be seen as ambiguous (fertilizer of parts of the world?)
2) D compares "use" to "usage" while A compares "use" to "increase"

D is not a great choice, as Stacey describes, but I think it's less problematic than A is.

Hi Ron,

Cant we say that the "this substitution" is modifying "while if substituted for more traditional fertilizers"

D. the increased usage of these fertilizers can create serious environmental problems such as water pollution, while if substituted for more traditional fertilizers, this substitution

similar to

Because she knew many of the leaders of colonial America and the American Revolution personally, Mercy Otis Warren was continually at or near the center of political events from 1765 to 1789, and this vantage point, combined with her talent for writing, made her one of the most valuable historians of the ear.

I cant understand why A is correct... As Rey pointed out - usage of their ??

also could you please explain if we can compare use to usage/ use to increase ????

look at just this part of choice d:

you can't do this.
if you precede a clause with an initial modifier that doesn't have a subject, then the noun IMMEDIATELY FOLLOWING THE COMMA is automatically assigned as the subject of that modifier.
so:
in this choice, you're saying, weirdly enough, that 'this substitution' is 'substituted' for more traditional fertilizers.
that doesn't make sense, as i'm sure you'll agree.



i'm not quite sure what you're asking here.

:twisted:
:evil: :evil: :evil:
U R THE BEST ,RON :roll:

gmat_s, Please do not confuse us, the OA is A, and not D.

A is better than D. D has problem : whereas - while : redudant

"their" in A is Ok .
the use of synthetic fertilizers, their use ...and their substitution.

Tutor, please explain "their" .

Thanks

"Their" is a 3rd person plural possessive pronoun. It replaces "synthetic fertilizers".

-Jon

Hello,

Is the usage 'their substitution for more traditional fertilizers ' in A correct?

Can you help me understand with some other example in the form of a sentence.

Thank you!