Solar Energy

Question

There is substantial evidence that certain forms of solar energy either now or within a few years will be economically competitive with conventional sources of heat and power.

(A) either now or within a few years will be economically competitive with conventional sources of heat and power
(B) will either be economically competitive with conventional sources of heat and power within a few years or are so now
(C) will be economically competitive with conventional sources of heat and power either now or within a few years
(D) either are now economically competitive with conventional sources of heat and power or will be so within a few years
(E) are either now or will be within a few years economically competitive with conventional sources of heat and power

I have seen discussion threads but I still have one question, and hope an expert can help me out. With answer D, the two branches "either..or" should read separately, and you get the following

1) There is substantial evidence that certain forms of solar energy are now economically competitive with conventional sources of heat and power
2) There is substantial evidence that certain forms of solar energy will be so within a few years

With 2) does the word "so" act as a pronoun referring back "economically competitive with conventional sources of heat and power"

Appreciate any assistance - Thanks

guha.santanu@gmail.com · Answer

D sounds awkward but it is grammatically correct and also maintains parallelism.

(either + auxiliary verb + time) + (or + auxiliary verb + time)

Statemetn C changes the meaning of the sentence. It means that certain thing is not yet economical and it will be economical from now onwards. Whereas real statements states that the certain thing (certain form of solar energy) is economical in present time. Statement (D) holds the meaning of the original statement hence it is correct over here.

e-GMAT · Answer

shamanth wrote:With 2) does the word "so" act as a pronoun referring back "economically competitive with conventional sources of heat and power"

Hi,

In the sentence 2 provided by you as well as in the original sentence, "so" is referring to "economically competitive with conventional sources of heat and power". Note that pronouns can only refer back to nouns or other pronouns. Here, "economically competitive with conventional sources of heat and power" is not a noun phrase. "economically" is adverb that is referring to "competitive", an adjective. We cannot use any pronoun here. Hence "so" has been aptly used to refer to this phrase.

Hope this helps.
Shraddha

jgmatk · Answer

shamanth wrote:There is substantial evidence that certain forms of solar energy either now or within a few years will be economically competitive with conventional sources of heat and power.

(A) either now or within a few years will be economically competitive with conventional sources of heat and power
(B) will either be economically competitive with conventional sources of heat and power within a few years or are so now
(C) will be economically competitive with conventional sources of heat and power either now or within a few years
(D) either are now economically competitive with conventional sources of heat and power or will be so within a few years
(E) are either now or will be within a few years economically competitive with conventional sources of heat and power

I have a question about option (A).
Is it right that option (A) is wrong or awkward not because "either now or within a few years" is located before Verb, but because "now" is awkward with future tense "will be"?

shamanth · Answer

jgmatk wrote:shamanth wrote:There is substantial evidence that certain forms of solar energy either now or within a few years will be economically competitive with conventional sources of heat and power. (A) either now or within a few years will be economically competitive with conventional sources of heat and power (B) will either be economically competitive with conventional sources of heat and power within a few years or are so now (C) will be economically competitive with conventional sources of heat and power either now or within a few years (D) either are now economically competitive with conventional sources of heat and power or will be so within a few years (E) are either now or will be within a few years economically competitive with conventional sources of heat and power I have a question about option (A). Is it right that option (A) is wrong or awkward not because "either now or within a few years" is located before Verb, but because "now" is awkward with future tense "will be"? Indeed - the latter is the reason, you cant say "now will be" its either now or will be in the future.... - hope this helps.

jgmatk · Answer

shamanth wrote:jgmatk wrote:shamanth wrote:There is substantial evidence that certain forms of solar energy either now or within a few years will be economically competitive with conventional sources of heat and power. (A) either now or within a few years will be economically competitive with conventional sources of heat and power (B) will either be economically competitive with conventional sources of heat and power within a few years or are so now (C) will be economically competitive with conventional sources of heat and power either now or within a few years (D) either are now economically competitive with conventional sources of heat and power or will be so within a few years (E) are either now or will be within a few years economically competitive with conventional sources of heat and power I have a question about option (A). Is it right that option (A) is wrong or awkward not because "either now or within a few years" is located before Verb, but because "now" is awkward with future tense "will be"? Indeed - the latter is the reason, you cant say "now will be" its either now or will be in the future.... - hope this helps. It helps a lot. Thank you, Shamanth.

Choose how you want to prepare

Get Ready for GMAT Test Day Faster with Live Online Classes

Target Test Prep EA OnDemand

Sep 6 to Dec 6, 2026

Target Test Prep GMAT OnDemand

Solar Energy

GMAT/MBA Expert

Chicago Booth

GMAT Course Reviews

Admissions Consulting Reviews

FREE GMAT PREP RESOURCES

GMAT PREP DEAL TRACKER