Unlike emergency calls that travel through regular telephone

Question

Unlike emergency calls that travel through regular telephone  lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller .

A. lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller

B. lines and thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller

C. lines, thus automatically informing the operator of the location and phone number of the caller, the location of a caller on a cellular phone has to be determined by the operator

D. lines, and thus automatically inform the operator of the location and phone number of the caller, emergency operators have to determine the location of the cellular phone caller

E. lines, thus automatically informing the operator of the location and phone number of the caller, emergency operators receiving a cellular call have to determine the location of the caller

Rock750 · Answer

Unlike X, Y 
X= emergency calls
Y= cellular calls
A- Wrong because of the usage of "they" 
B- Correct
C- Wrong, Parrellisme issue : travel // informing 
D- Wrong, remember Unlike X, Y : in this option, we are comparing "emergency calls" and "emergency operators"
E- Wrong, same issue in C and D

So, the correct answer should be B

sony26 · Answer

Hi,

In A - 'where they ' is incorrect usage
Sentence starts with 'Unlike emergency calls', so comparison should be with 'cellular calls'.
In C the comparison is with  location of a caller 
In D and E, the comparison is with  emergency operators.

So,  B  should be the right answer.

Regds
Sony

aquarius24 · Answer

Unlike emergency calls that travel through regular telephone lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller.

In the para emergency calls should be compare with "some sort of calls" i.e. after second comma there should be noun (for some type of calls)

Thus makes C,D and E out

Now in A "they" creating a confusion for anteceedent which is clear in B

So my take B

mohit878 · Answer

We are comparing emergency calls with cellular calls...So only option B seems correct.

sairam595 · Answer

Does the usage of "where" correct here!
pls advise

Skywalker18 · Answer

Unlike emergency calls that travel through regular telephone  lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller .

A. lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller -- usage of where is incorrect

B. lines and thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller - Correct

C. lines, thus automatically informing the operator of the location and phone number of the caller, the location of a caller on a cellular phone has to be determined by the operator- Emergency calls and location of a caller are not parallel

D. lines, and thus automatically inform the operator of the location and phone number of the caller, emergency operators have to determine the location of the cellular phone caller- Emergency calls and emergency operators are not parallel

E. lines, thus automatically informing the operator of the location and phone number of the caller, emergency operators receiving a cellular call have to determine the location of the caller - same as D

Answer B

teaserbae · Answer

Skywalker18 
isn't the use of they ambiguous in A

ayushkumar22941 · Answer

inform is better than informed and option d and e has parallelism error so b is correct option.

fireagablast · Answer

Unlike emergency calls  that travel through regular telephone lines, where they thus automatically inform the operator of the location and phone number of the caller,  cellular calls  require emergency operators to determine the location of the caller.

A. lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller - Wong because "where" is used to describe a thing and can only be used to describe a place, "and" adding they is poor grammar in this situation.

B. lines and thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller - Better, it maintains the structure of "Unlike this, that" and lines up Emergency calls and Cellular calls

C. lines, thus automatically informing the operator of the location and phone number of the caller, the location of a caller on a cellular phone has to be determined by the operator - Biggest problem here is that we've changed to "UNLIKE emergency calls, cellular calls" to "UNLIKE emergency calls, the location". No longer making an apt comparison.

D. lines, and thus automatically inform the operator of the location and phone number of the caller, emergency operators have to determine the location of the cellular phone caller - and thus would mean in addition too, rather than result of. Also "UNLIKE emergency calls, emergency operators" is wrong.

E. lines, thus automatically informing the operator of the location and phone number of the caller, emergency operators receiving a cellular call have to determine the location of the caller - again wrong "UNLIKE emergency calls, emergency operators".

Can someone please confirm this thought below?
generally all of them are also incorrect (except B) because if you do "1st-noun clause1a, thus clause1b, 2nd-noun" you are incorrectly attributing clause1a to noun2.

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Unlike emergency calls that travel through regular telephone

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Sentence Correction (SC - EA only) Questions

Unlike emergency calls that travel through regular telephone

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards