Unlike emergency calls that travel through regular telephone

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

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

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

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

Skywalker18
isn't the use of they ambiguous in A

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

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.

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