One manufacturer has announced plans to increase the average fuel efficiency of its sport utility vehicles by 25 percent over the next five years, amounting to roughly five miles per gallon, and representing the first significant change in the fuel efficiency of any class of passenger vehicle in almost two decades.

(a) amounting to roughly five miles per gallon, and representing
(b) amounting to roughly five miles per gallon, and it would represent
(c) an increase that would amount to roughly five miles per gallon and it would represent
(d) an increase that would amount to roughly five miles per gallon and would represent
(e) which is an increase amounting to roughly five miles per gallon, representing

Was able to eliminate A and B because "amounting" is present tense while the company has only announced to increase fuel efficiency.
Eliminated E because "which" refers to years

Could not decide between C and D. Please explain

Actually, "amounting" is not a tensed verb at all. It's a present participle -- a grammatical object formed from a verb but that can take on a number of grammatical functions. Here, it's being used to start a modifying phrase. The essential question: what is it modifying?

In A and B, a comma followed by a present participle "...years, amounting to..." suggests one of two scenarios: either the phrase is an adverbial modifier that modifies the preceding verb "has announced" OR it's an adverbial modifier that modifies the entire preceding clause, "One manufacturer... five years". The trouble with A and B, therefore, is that neither possibility makes any sense. "amounting to..." doesn't modify "has announced" and it also doesn't modify the entire clause.

E uses the relative pronoun "which." As written, its antecedent would be "years" and that makes no sense in the sentence.

C and D fix the problem by introducing "an increase." Now, "amounting to..." is a noun modifier that modifies "an increase." Eliminate A, B, and E.

Between C and D, eliminate C because it introduces an ambiguous pronoun "it." I'd go for D.

Well.



Is it a typo mistake that answer choice "D" the right answer lacks a THAT after second AND:
an increase that would amount to roughly five miles per gallon and that would represent.
if it is not then why it is like this? pls explain

pls shed some more light on A. Especially give some example pls.

no, no mistake.

there are two kinds of parallel signals: ONE-PART (such as "and", "or", "but"), and TWO-PART (such as "not only ... but also", "both ... and").

when you have PARALLELISM WITH A ONE-PART SIGNAL, the only words that are "locked in" are the ones directly FOLLOWING the signal.
as long as you can find the corresponding structure in the other part, then the parallelism is fine.

examples:
i worked in nevada and florida.
i worked in nevada and in florida.

BOTH OF THESE ARE FINE.

reasons:
in the first, the part that's "locked in" by the signal and is just florida. therefore, the parallel construction would be just nevada.
since that construction is there, the sentence is parallel:
i worked in
nevada
and
florida.

in the second, the part that's "locked in" by the signal and is in florida. therefore, the parallel construction would be just in nevada.
since that construction is there, the sentence is parallel:
i worked
in nevada
and
in florida.

--

for completely analogous reasons, this sentence would be fine either with or without your second "that":

an increase that
would amount to roughly five miles per gallon
and
would represent...

an increase
that would amount to roughly five miles per gallon
and
that would represent...

Dose whether...or belongs to ONE-PART or TWO-PART?
#1 She was uncertain whether to stay or leave.
#2 She was uncertain whether to stay or to leave.

which one is correct or they both correct?

there is a PREP question about this issue:

The ecosystems of barrier islands are extremely vulnerable--whether from natural processes like shoreline recession, rising sea levels, and destructive hurricanes, or the ever-increasing pressures of development.

(B) whether from natural processes such as shoreline recession, rising sea levels, and destructive hurricanes, or also
(E) to natural processes such as shoreline recession, rising sea levels, and destructive hurricanes, as well as to

OA is E!
is B' ill parallel for inserting new also or not repeating from?

Technically, can we view "amounting to" as an adverbial modifier for "to increase", a non-finitive verb structure?
In choice B of this question(1000-sc-31-t1988.html?hilit=through%20a%20red%20giant%20stage,%20depending%20on%20mass), the "doing" adverbial modifier does modify a non-finitive verb.
Thanks!

super explanation(s). Thanks a lot Ron.

I believe that "whether ... or" is also a two-part construction: the words following "whether" it should be parallel in form and context to those following "or". I would like to see some evidence one way or the other, though.

Still, choice (B) has all sorts of problems here. First, you can't idiomatically combine "vulnerable" with "from". Second, "or also" doesn't really make sense here.
But, yes, I think that the lack of parallelism of the constructions following "whether" and "or" is also sufficient grounds for eliminating this choice.