A is in passive voice and B is in active voice. the justification for A may be that light cannot shift on its own, it has to be shifted by some agent and hence the preference for passive voice.

(i fell for B )

I'm not a grammar guru but i think the following would be the reasoning:

"Has been" indicates the some force has shifted the light. Here it means that the light itself has been shifted by the rapid movements.


"Has shifted" indicates that the light has shifted something. It doesn't clearly mean that the light itself has been shifted.

Wow !!! Great question again. What is the source buddy?

I too chose B, but after seeing the OA, I realised that the shift occured because of the rapid motion of the galaxy away from the Earth. Since something caused the shift, "has been shifted" is the correct usage.

well Thanks for your replies friends.

The source is OG-10th edition

I was able to find an explanation once I saw the OA But the thing is.....how will you attack this question when you see them in for exam screen.

I want to learn the strategy for attacking this type of question

gmat740 wrote:well Thanks for your replies friends.

The source is OG-10th edition

I was able to find an explanation once I saw the OA But the thing is.....how will you attack this question when you see them in for exam screen.

I want to learn the strategy for attacking this type of question

Hey Karan,

One simple strategy is to focus. I have observed from my mistakes that most of the times because I am on the lookout for errors, I tend to not understand the meaning of the sentence & so pick up an answer that seems correct. In this case, B is contextually wrong, but not grammatically. So, we need to practice to read the sentences properly (trying to understand what the author is trying to convey) & then grammatically correct it.

I thought 'which' had to be preceded by a comma? :

I still have a little concern regarding this question. The OG 10th Ed explains as follows:

Choice A is best because it is idiomatic and because its passive verb construction, has been shifted, clearly indicates that the light has been acted upon by the rapid motion.

In B, the active verb has shifted suggests that the light, not the motion, is the agency of action, but such a construction leaves the phrase by the rapid motion of the galaxy away from the Earth without any logical or grammatical function.

In C, the construction the extent that light is ungrammatical; denotes the extent must be completed by to which.

D incorrectly employs an active verb, shifting, and extent of light is imprecise and awkward.

E is faulty because it contains no verb to express the action performed by the rapid motion.

Does anyone know why "denotes the extend" must be completed by "to which"? After searching on Google, I cannot find any idiom in relation to either "denote" or "the extend".

Many thanks.

the issue is not with an idiom of denote or extent itself, but rather with the continuation of the sentence "by the rapid motion of the galaxy away from the Earth." the 'by" indicates that some action has been done BY the motion, requiring the passive form for the previous verb.

Do not be quick to look for idioms - in many cases, idioms are inserted into an SC question just to drag you into playing on the wrong field, that of playing things by ear. Often, there's a stronger reason to eliminate all of the wrong answers and leave yourself with a single right answer. Delay decisions about "idiomatic" reasons to eliminate answer choices until you really have to - focus on other, more solid grammar/logic/style/fit into the rest of the sentence reasons to eliminate an answer choice. If, after looking at the answer choices carefully, yo cannot find a reason to eliminate one or the other, guess by "which idiom sounds better".

inactived wrote:I still have a little concern regarding this question. The OG 10th Ed explains as follows:

Choice A is best because it is idiomatic and because its passive verb construction, has been shifted, clearly indicates that the light has been acted upon by the rapid motion.

In B, the active verb has shifted suggests that the light, not the motion, is the agency of action, but such a construction leaves the phrase by the rapid motion of the galaxy away from the Earth without any logical or grammatical function.

In C, the construction the extent that light is ungrammatical; denotes the extent must be completed by to which.

D incorrectly employs an active verb, shifting, and extent of light is imprecise and awkward.

E is faulty because it contains no verb to express the action performed by the rapid motion.

Does anyone know why "denotes the extend" must be completed by "to which"? After searching on Google, I cannot find any idiom in relation to either "denote" or "the extend".

Many thanks.

Just realized i didn't really answer your question. My previous post notwithstanding, C is indeed eliminated by idiom: "to what extent light has been shifted away from red", which is why you need the preposition "to" in the construction of the relative clause.

Geva@MasterGMAT wrote:the issue is not with an idiom of denote or extent itself, but rather with the continuation of the sentence "by the rapid motion of the galaxy away from the Earth." the 'by" indicates that some action has been done BY the motion, requiring the passive form for the previous verb.

Do not be quick to look for idioms - in many cases, idioms are inserted into an SC question just to drag you into playing on the wrong field, that of playing things by ear. Often, there's a stronger reason to eliminate all of the wrong answers and leave yourself with a single right answer. Delay decisions about "idiomatic" reasons to eliminate answer choices until you really have to - focus on other, more solid grammar/logic/style/fit into the rest of the sentence reasons to eliminate an answer choice. If, after looking at the answer choices carefully, yo cannot find a reason to eliminate one or the other, guess by "which idiom sounds better".

inactived wrote:I still have a little concern regarding this question. The OG 10th Ed explains as follows:

Choice A is best because it is idiomatic and because its passive verb construction, has been shifted, clearly indicates that the light has been acted upon by the rapid motion.

In B, the active verb has shifted suggests that the light, not the motion, is the agency of action, but such a construction leaves the phrase by the rapid motion of the galaxy away from the Earth without any logical or grammatical function.

In C, the construction the extent that light is ungrammatical; denotes the extent must be completed by to which.

D incorrectly employs an active verb, shifting, and extent of light is imprecise and awkward.

E is faulty because it contains no verb to express the action performed by the rapid motion.

Does anyone know why "denotes the extend" must be completed by "to which"? After searching on Google, I cannot find any idiom in relation to either "denote" or "the extend".

Many thanks.

yeloaw wrote:I thought 'which' had to be preceded by a comma? :

not necessarily, preposition (during, in, from ect...in this case to) +which goes well!