The new model of dark matter reactivity hopefully can provide sufficie

OFFICIAL EXPLANATION



• it is hoped

GMAC does not like the way that most people use word "hopefully."

And the issue is tested. I know that experts have said that GMAC does not test the issue.
That information is out of date.
The Advanced Questions published in September of 2019 contained one question in which "hopefully" and "it is hoped" were tested.
That question is herel.
A better and recent question is listed in Notes, below.
I can think of two more such quesitons, and I suspect that there are more than those four.

• hopefully, hopefully, it is hoped

-- 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" (is doing something in a hopeful manner)?
No one and nothing.
Models of dark matter do not display hopefully behavior.

Hopefully cannot modify a whole clause.
Wrong: Hopefully, the weather will be sunny for the picnic tomorrow.
→ The weather cannot feel hopeful, be hopeful, or behave hopefully.
Wrong: Hopefully, you can follow instructions.
Correct: I hope that you can follow instructions.

Finally, we use "it is hoped" to (1) replace "hopefully" in its correct usage, usage that
(2) usually means "I hope that" or "we hope that."
English speakers have a really hard time with this guideline.
They want the "hopefully" to be part of the general atmosphere: fine. Use "it is hoped."
-- you can call the "it" a dummy pronoun or a pronoun with a delayed antecedent
-- I don't see the point in the latter. The word IT is a placeholder. The end.

Although "hopefully" is okay in informal conversation and according to some grammarians,
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.)
Use "it is hoped," ften placed in the middle of a sentence and set off by commas.

• watch for comma splices, poor construction, and removal of essential information

THE PROMPT
The new model of dark matter reactivity hopefully can provide sufficient evidence, this will put to rest the age-old debate on the existence of antimatter.

THE OPTIONS


• Two independent clauses must be joined with comma + conjunction. No conjunction exists. The two ICs are "stuck" together improperly.
This incorrect construction is called a "comma splice" or "run-on sentence."
• What, exactly is "hopefully" providing sufficient evidence for XYZ?
The new model of dark matter? No. A model of dark matter does not behave hopefully.
Eliminate A


• The clause it is hoped should be either separated with commas (as in answer C) or connected with an appropriate conjunction.
Eliminate B


• it is hoped is correctly set off by commas
• this construction "splits the verb." I talk about this (allowed) splitting in this post, here.
KEEP

• the model of dark matter did not do anything hopefully.
The model is inanimate.
• what happened to "suffcient evidence"?
Eliminate D


• A model of dark matter does not itself hope to do anything.
• What happened to sufficient evidence? I ask not because A determined original meaning.
(A) does not determine original meaning.
But we do have three options that include extra information that seems very essential in context.
Eliminate E.

The correct answer is (C).

• NOTES

The official question on which this is based—in which the word "hopefully" is tested as of September 2019—is here.
The official question is good.

In my response, you will read about some layers of rhetorical construction.
The question is interesting.
The prose in that question is good.

Doer01 , well done! Thank you for taking the time to research the issue.

I think that when Mike McGarry wrote that post, he had not seen the question to which I linked. The question was republished in September 2019 in the Advanced Guide.
There are at least two other official questions that test this issue.

• This phrase is common in academic English: [b][color=#0000ff]will, it is hoped, VERB[/color][/b]

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.
this post, here.

This example comes from the New York Times 
[In addition to numerous changes designed to ease airplane congestion] specially trained ground controllers will, it is hoped, speed up the flow of traffic from New York on routes to the Middle West.
“A Plan to Unlock the Great Grid in the Skies.” New York Times. 31 March 1985. (1985) Available at this address. Accessed Dec 10 2019.

COMMENTS

Camach700 . welcome to SC Butler.

globaldesi , as I wrote above, option D
(1) gets "hopefully" wrong, as zhanbo helpfully affirmed,
and
(2) Options D and E removes information that is essential. We can tell that the information is essential both by comparing D and E to the other three options.
THe essential/nonessential distinction still holds for now:
OG 2020 includes a question (SC# 824) in which essential vs. non-essential information is tested explicitly. .

The usage of hopefully is not a matter of idiom.
Hopefully is an adverb.
A living, sentient being can do something hopefully.

----
When I peeked earlier, only the first three people had posted -- eakabuah , Camach700 , and Doer01 - very well done.

Kudos go to all good explanations—which, at last count, was all of you.