The use of gravity waves, which do not interact with matter in the way

Note: for straight process of elimination, scroll to the bottom of the post

Hi dave13 ,
Generally: In Option B, we are dealing with a construction called "splitting the verb." See the analysis and the link below.

• (B) - wordy and awkward? Still better than "wrong answer."

I kinda understand about the "awkward and wordy" part.
On the other hand, if you are not sure about the word "hopefully"—and many people aren't—pick "hopefully" to eliminate,
as long as the "it is hoped" option seems grammatical otherwise.

Hopefully is an adverb, this way: He looked hopefully towards the horizon, waiting for sunrise.
Hopeful is the adjective. The hopeful sailors scanned the horizon for land.
In this question, who or what is doing something "hopefully" here (is doing something in a hopeful manner)?
The electromagnetic waves?
No. Although "hopefully" is okay in informal conversation and according to some grammarians,
all the time, the GMAT does not like hopefully unless it is attached to a person doing something with hope.
(I do not think I have ever seen an official question with "hopefully" in the correct answer.)

What if a test taker is not sure whether a word in one answer is correct and the other answer
sounds wordy and awkward?
Choose the "wordy" and "awkward" answer.
"Wordy and awkward" sentences aren't great. But they aren't wrong.

• What do we call the construction or style in option B? That construction is called "splitting the verb"
You have asked a really hard question.
Style and rhetoric questions delve into difficult material. I have no doubt that you can handle it.

What you see is called "splitting the verb."

We split a helping (auxiliary) verb from the other verb and put an adverb or short adverbial phrase
to clarify, to emphasize, or to avoid awkward constructions.

Normally, adverbs in auxiliary verb-verb constructs come after the verb.
Correct: We have fixed that part already. [Do not fix that part again. Please fix a different part.]
For emphasis: We have already fixed that part. [So you should not fix it again. Please fix a different part.]
Also for emphasis: We already have fixed that part. [Before now, we fixed that part.]

In the emphasis cases, I split the auxiliary verb have from the verb fixed.
The word "already" gets the reader's or listener's attention.

Short phrases can also be inserted.
→ I just split the verb "can be" with "also"

In this case, "it is hoped" correctly splits the verb as I explain below.

One note of caution: splitting verbs with adverbs can produce confusion.

An excellent synopsis can be found HERE. The synopsis deals with splitting verbs,
as is done in "will, it is hoped, enable."
The article simplifies the whole topic and describes the possibility of confusion.

• Splitting the verb in this question

The auxiliary verb "will" is split from the main verb "enable" by the adverbial phrase it is hoped probably for two reasons:

1) to qualify, explicitly, an extraordinary assertion.
Think about seeing the formation of black holes!
The author wants to remind us that this event is not certain (clarity)
but very exciting (emphasis);
and
2) to maintain flow. Stylistically, the phrase does not work very well elsewhere.

• This phrase is common in academic English: will, it is hoped, VERB

The construction looks strange to many.
If you read enough stuffy or scientific literature, the phrase does not seem strange. (Guilty as charged.)
Other phrases that split verbs in formal prose include on occasion, in theory, and in reality.

Such splitting is allowed and often used to add particular emphasis or to avoid strange phrasing.

• Trying to move it is hoped creates problems
If we try to rewrite the sentence, to change the split verb, we run into problems.

• Rewrite #1. The sentence could be rewritten this way:

(1) It is hoped that the use of gravity waves, which do not present the problems that X do, will enable astronomers to study Y and Z.

The author wants to emphasize the importance of gravity waves' potential to allow human beings to witness the formation of black holes and neutron stars (Y and Z).
-- (S)he partly accomplishes her goal by keeping what astronomers will be able to study at the end of the sentence.
(In English, readers naturally stress the end of a sentence most of the time.)

-- The phrase's placement in (1), however, puts too much stress on "it is hoped."
There is too much stress on "it is hoped" because the sentence leads with a hypothetical—and one without an agent at that.

• So let's try a different placement of the adverbial phrase "it is hoped." Rewrite #2:

(2) The use of gravity waves, which do not interact with matter in the way electromagnetic waves do, will enable, it is hoped, astronomers to study Y and Z.

Unless the object is long or complex, an adverb should not intrude between a verb (enable) and the verb's object (astronomers).

Now the adverb "it is hoped" is clumsy and a buttinsky.

This writer wants to talk about radical horizons.
The connection between "enable" and astronomers" is blocked.
An adverb between verb and an object is often nonsensical.
Incorrect: The team rejected summarily him during the draft pick rounds.

• Let's move the phrase again. Rewrite #3

(3) The use of gravity waves, which do not interact with matter in the way electromagnetic waves do, it is hoped will enable astronomers to study the actual formation of black holes and neutron stars.

The author wants to focus on the potential for astronomers to study Y and Z.
(S)he has to qualify an assertion, but in this sentence the phrase disconnects the logical connection between waves and will enable.

Further, if we place it is hoped after the comma and before the auxiliary verb phrase, that placement suggests an antecedent of "it."
No such antecedent exists. "It" is a dummy placeholder.
The phrase draws unearned attention in this third case.

• We have a better choice of placement. The author qualifies an exciting assertion in the correct manner
by suggesting the uncertainty without harping on it.

The use of gravity waves, which do not interact with matter in the way electromagnetic waves do, will, it is hoped, enable astronomers to study the actual formation of black holes and neutron stars.
By way of rhetorical and syntactic effect, the reader discovers an exciting prospect.

This prospect (future, declarative) WILL, it is hoped, ENABLE.
Those two capitalized words draw our attention.

The placement of "it is hoped," between a declared future and a Good Thing,
allows us to absorb a sense of measured determination. That is, the scientists are confident about but not guaranteeing a result.

Black holes and neutron stars fascinate me.

Even with many commas in its sentence, the placement of "will, it is hoped, enable" mimics a human being who waits with bated breath to see the formation of a black hole.

---------
And if none of that explanation satisfies you, rely on POE. :-D
• Process of Elimination

Split #1: LIKE is incorrect

One cue comes from a phrase in Options A and B: in the way [that].
That very phrase is a good way to test whether we should use the word AS or LIKE (in options C and D).
in the way that = AS
If in the way that works, then the word as is correct and the word like is wrong.
In comparisons, like is followed only by a noun and does not take a verb.
→ in order to remember, think "like = similar TO." Similar to what? To some noun, possibly in a noun phrase.
In the way that or describes actions—verbs!

Substitute "in the way that" for LIKE to see whether LIKE is correct.
If the sentence works with "in the way that," we are implying an action, and like should not be used.
C) . . . gravity waves, which do not interact with matter [in the way] electromagnetic waves, hopefully . . . [that substitution works. LIKE is wrong.]
D). . . gravity waves, which do not interact with matter [in the way] electromagnetic waves . . . [that substitution works. LIKE is wrong]

We have two cases of a Missing Verb.
We need AS electromagnetic waves DO.

Omit C and D

Split #2: SUCH AS is for examples, not for direct comparison.
The contrast is between gravity waves and electromagnetic waves. The latter are not an "example." The latter are the other item of comparison.
SUCH AS . . . electromagnetic waves DO is incorrect

Omit E

Split #3 - Hopefully is an adverb and things cannot act or behave hopefully.

The use of gravity waves . . . hopefully will enable
What, the gravity waves will be hopeful when those gravity waves enable astronomers to witness the formation of black holes? I don't think so.
Worse, the use of the gravity waves will behave hopefully when that use helps? No.

Correct: I hope, they hope, scientists hope (verb)
Correct: I am hopeful about the future, scientists are hopeful about the prospect of learning more about black holes (adjective)
Correct: The seasick tourist looked hopefully at the island towards which the boat was heading. (adverb)
Correct: it is hoped

Wrong: The use of gravity waves . . .hopefully will enable
-- Will the gravity waves enable in a hopeful way = hopefully?? NO
Wrong: The use of gravity waves . . . would enable, hopefully.
-- The use of gravity waves will not help hopefully. A thing cannot do something in a hopeful manner = hopefully.

Incorrect: hopefully in A, C, and E. (C and E are already gone)

Omit A.

The answer is B.

I hope that analysis helps.