Although at one time children’s programming had been limited to a few hours a week, now, however, there are at least four cable networks that dedicate themselves entirely to shows produced specifically for children.
A.Although at one time children’s programming had been limited to a few hours a week, now, however, there are at least four cable networks that dedicate themselves
B.With children’s programming having been limited at one time to a few hours a week, now at least four cable networks have dedicated themselves
C. Once limited to a few hours a week, there are now at least four cable networks with children’s programming that dedicate themselves
D. Children’s programming was once limited to a few hours a week, but now there are at least four cable networks dedicated
E. While children’s programming had once been limited to a few hours a week, at least four cable networks are now dedicated
OA is D. I wish to know what is wrong with D?
Thanks

If the OA is D, there should not be anything wrong with (D).

A) Past perfect 'had been limited' is wrong. Since the phrase begins with 'Although', 'however' is redundant.
B) Present perfect 'Having been limited' is wrong. The limit no longer exists.
C) Misplaced Modifer. 'Once limited to ...' should refer to children's programming.
D) Correct - Tense is correct. We have two independent clauses joined by coordinating conjunction 'but'.
E) Use of Past perfect tense.

Let's see what the MGMAT instructors have to say.

Guest,
I am sorry. Thanks
I meant E.
I wonder whether "Once" is used in simple past

choice e is incorrect because of its inappropriate use of the past perfect. if you're going to say kids' programming had once been limited to ..., then you must reference a second past event. this sentence doesn't do that: the second event referenced is in the present (specifically, 'now').

what is wrong with A?

Exactly the same as E. See Ron's explanation of E above.

Why is 'now dedicatED' a proper construction for something that is happening in the present? I know it sounds correct to the ear. Just trying to understand grammatical rule behind it.

this is an example of a "participle".

there are two kinds of participles:
* -ING forms (which are called "present participles");
* "past participles" (usually -ED forms, although there are some irregular ones, such as taken, thrown, seen, been, etc.)

despite their names, participles are not actually tensed forms.
in other words, the participles don't commit to any particular tense. of particular note is the fact that "present participles" are not necessarily in the present tense, and "past participles" are not necessarily in the past tense.
instead, they are COMPLETELY DETERMINED BY CONTEXT. they are "anchored" by the verbs in the sentence that actually have TENSES.

examples (i'll use a "present participle", although the same sort of variety can also be found among "past participles"):

100 years ago, students writing papers used quill pens. --> in this case, "writing" is actually a past tense construction, since it is "anchored" by the past tense verb "used".

Nowadays, students writing papers use word-processing programs such as Microsoft Word. -> in this case, "writing" is a present tense construction, since it is "anchored" by the present tense verb "use".

In 20 years, students writing papers will use voice dictation software. --> in this case, "writing" is a future tense construction, since it is "anchored" by the future tense verb "will use".

--

this is, by the way, an absolutely perfect illustration of why you shouldn't concentrate at all on the NAMES of grammatical constructions; the names of these two kinds of constructions are actually lying to you.
instead, just learn to recognize correct and incorrect forms on sight, and don't worry about slapping labels on them.

Hi Ron, In E, is it correct to say that "are" after the word "But" is parallel to "Was" since they are both tensed ?

hmm?

i don't see the word "but" anywhere in choice (e).

Past perfect form in a sentence can only be moved into the future by one step so that past perfect becomes past
E.g: had been --> was

Past form in a sentence can only be moved into the future by one step so that past becomes present
E.g: was --> is

Present form in a sentence can only be moved into the future by one step so that present becomes future
E.g: is --> will be

Are the above correct?

Thanks!

unfortunately, no, verb tenses are not that simple. if there are enough time transitions in the sentence, it's possible to move forward by more than one of these "steps" at a time.

for instance:
my uncle, who visited our family last october, will be in town again next month.

note that there are 2 time transitions in this sentence:
uncle's visit (in the past)
transition -->
the sentence is written in the present
transition -->
uncle will visit again (in the future)

if a sentence contains only one time transition, however, then your observations are probably accurate.

Ron,

I'm trying to understand the OA and how it parallel "there are " statement.

Is this a take away for parallelism

D. Children’s programming was once limited to a few hours a week, but now there are at least four cable networks dedicated

Children's programming ...is parallel to There (Four Cable network) are?

Thanks much

when you have "COMPLETE SENTENCE + , + and + COMPLETE SENTENCE" (or the same construction with “but”), the only thing that's absolutely required by parallelism is that both of the complete sentences be ... well, complete sentences.
if the parallelism can be extended in any obvious way -- e.g., if both complete sentences have similar elements that can be placed in the same order -- then it should be extended in that way. however, it should be clear that two parallel clauses don't have to be written entirely in the same grammatical form; if that were required, it would be nearly impossible to write any compound sentences!

C > Once limited to a few hours a week, there are now at least four cable networks with children’s programming that dedicate themselves

I can see C has a miplaced modifer.
Also is C wrong because that is referring to children's programming instead of cable networks ?

Is there any exception to touch modification using - "that" ? I've read Ron's post that describes how a prepostional phrase may separate "which" from its subject. Are any such constructions allowed with "that" ?