Computers are becoming faster, more powerful, and more reliable,and so too are modems, they are the devices to allow two or more computers to share information over regular telephone lines.

(A) so too are modems, they are the devices to allow
(B) so too are modems, the devices that allow
(C) so too modems, the devices allowing
(D) also modems, they are the devices that allow
(E) also modems, which are the devices to allow

OA is B.

OG explanation -

The original sentence is incorrect due to several reasons, and one of them is that in the following part of the 'so too are modems, they are.....lines'. Introduction of 'they are' is making a Run-on sentence. And (B) is introducing the clause correctly.

My question -

In (B) - 'so too are modems, the devices that allow two or more computers to share information over regular telephone lines.'

so too are modems - is a clause and what is the function of 'the devices that allow two or more computers to share information over regular telephone lines.' Is it a phrase that is acting as an adjective for the noun 'modems'. And so makes - 'so too are modems, the devices that allow two or more computers to share information over regular telephone lines.' a single clause and corrects the problem?

Can someone/instructors explain?

Thanks

Let me give it a try. The comma between modems and they is trying to join the two Independent Clause.

Clause 1 # Computers are becoming faster, more powerful, and more reliable,and so too are modems
Clause 2 # They are the devices to allow two or more computers to share information over regular telephone lines.

This is a comma splice. A comma splice is the use of a comma between two independent clauses. You can fix comma splice by various ways such as :

(A) We can separate the two clauses into two sentences by replacing the comma with a period OR
(B) We can replace the comma with a semi-colon.
(C) We can replace the comma with a co-ordinating conjunction (and, but etc.)
(D) We can replace the comma with a subordinating conjunction (e.g., because, when etc.).


Incorrect: I like this class, it is very interesting.

Correct: I like this class. It is very interesting.

(or) I like this class; it is very interesting.

(or) I like this class, and it is very interesting.

(or) I like this class because it is very interesting.

(or) Because it is very interesting, I like this class.


Hope that helps !

" I am NOT an Grammar Expert". The instructors can comments for more clarification and/or corrections.

Thanks for the explanation Mridul, but my question is still unanswered. In context of this sentence and your explanation,
we know the comma splice has not been corrected by either replacing the comma with a period or by a semi-colon.

Are you saying the co-ordinating conjunction or sub-ordinating conjunction is used to combine the two clauses? If yes, what is the conjunction used here?

I believe - removing 'are' from the original clause, converts it into a phrase.

Can anyone/instructors explain?

Thanks

OK, let’s take a simple sentence and bisect it.

I like to read Archaeology books and I love to watch movies of Dinosaur, a reptile that lived in Jurassic age.

Independent Clause1 # I like to read Archaelogy books
Coordinate Conjuction # and
Independent Clause2 # I love to watch movies of Dinosaur
Modifier (adjective) # reptile
Restrictive Clause # that lived in Jurassic age

That is a relative pronoun referring to reptile.

So, in this structure restrictive clause tells us about the reptiles that lived in Jurassic age. There might be other reptiles but it restricts us to only those reptiles that lived in Jurassic age.

Combining all the last three elements ( highlighted in Red) DOES NOT means one big clause. It is just one thing modifying another thing which is again modified.

In the original sentence (Answer Choice B):

Independent Clause 1# Computers are becoming faster, more powerful, and more reliable
Coordinate Conjunction # and
Independent Clause 2# so too are modems
Modifier # the devices
Relative Clause (or more specifically restrictive Clause) # that allow two or more computers to share information over regular telephone lines.

Combining last three elements do not make a one big clause.

As a matter a matter of fact you can have a series of dependent clause modifying one thing after other OR modifying the same thing.

OK, let’s take a look into this sentence:

I would like to buy a 19 inch TV and I would like to buy iPOD, the music player that adds to my collection of cool electronic gadgets, one of my favorite hobbies.

Independent Clause # 1: I would like to buy a 19 inch TV
Independent Clause # 2: I would like to buy iPOD
Modifier 1 # the music player
Relative Clause # that adds to my collection of cool electronic gadgets.
Modifier 2 # One of my favorite hobbies


Modifying 2# (One of my favorite hobbies) is modifying the idea: collection of electronic gadgets” and telling that this “collection of electronic gadgets “is my hobby.
Modifier 1 # the music player is modifying the iPOD.

Hope that makes sense!

This is a common construction - the 'nonessential modifier,' set off from the word it describes by a comma. What makes it difficult here is its length.

Here's an easier-to-understand example:
(1) Helsinki, a city lying above 60 north latitude, enjoys extremely long summer days.
This is the most common way in which you'll encounter this type of modifier: directly after the INITIAL subject of a sentence. Notice that you can always insert WHICH IS/ARE or WHO IS/ARE into this construction: Helsinki, [WHICH IS] a city lying... These words, which serve as 'cognitive lubricant' in SPOKEN English, are unnecessary in written English and, if used in excess, are often considered a sign of immature writing.

Now try this:
(2) Helsinki, a city lying above 60 north latitude, enjoys longer summer days than does Copenhagen, a city situated at around 55 north latitude.

Notice where you can insert WHICH IS in this sentence.

--

Now go back, insert WHICH ARE into the correct answer, and check out the construction.