Please refer to the below thread :
forum/set26-37-sound-can-travel-through-water-for-enormous-77588.html

Hi Buddy : Plz find an explanation from the magical Stacey Koprince of MGMAT

The excerpt :

This is an OG question, so I can't discuss it directly, but I can discuss a similar sentence that I make up...

The debate here is between these two "types" of sentences:

1) Light can travel through space for huge distances, its energy prevented from dissipating by X.

2) Light can travel through space for huge distances, preventing its energy from dissipating by X.


Let's start with #1.
The word "prevented" can be a regular conjugated verb or it can be a participle. If it's a participle, it can be part of a verb form (with another conjugated verb before it) or it can indicate a modifier. Examples of the two verb options:

"prevented" as regular conjugated verb: I prevented my paper from blowing away.

Conjugated verb + "prevented" participle: My paper was prevented from blowing away. (The paper was prevented by me.)

Now, what is the difference in those two sentence constructions? The first is active; the second is passive. In the first, the subject (I) is doing the action (prevented). In the second, the subject (paper) is having the action performed on it (I'm still doing the preventing, not the paper).

Could I write: "The paper prevented from blowing away" - meaning, the paper prevented itself from blowing away? Nope. The paper can't prevent itself from blowing away. If we want to use "the paper" as the subject, we have to write this in passive voice.

So. Energy prevented from dissipating by X. Is that a sentence? Can the energy prevent itself from dissipating? No, again. If we want to use "energy" as a subject and have an independent clause here, we have to write this in passive voice, which would be "the energy WAS prevented from dissipating by X."

What does that mean? That word "prevented" is not a conjugated verb or part of a conjugated verb form in this sentence. Therefore, it's a modifier and the stuff after the comma in C is NOT an independent clause - it's the rest of the modifier.

Now, #2.
2) Light can travel through space for huge distances, preventing its energy from dissipating by X.

We have <independent clause>, <-ing modifier>. The -ing modifier needs to modify the preceding clause. Also, the modifier needs to follow from the independent clause; that is, something in the independent clause needs to be doing this "preventing." What is doing this preventing?

Argh. It's the stuff after the word "by." That's not part of the independent clause. Nothing in the independent clause is responsible for "preventing the energy from dissipating." This is a misplaced modifier.

If it's too confusing to understand based on the example above, try this:

Paper can fly through the air for huge distances, preventing it from falling by gusts of wind.

What's preventing the paper from falling? The gusts of wind. But the "preventing" has to refer to the stuff *before* the comma. Nothing *before* the comma is actually preventing the paper from falling.

3 is the answer.

1, 2 and 5..meaning is not right. sound is not preventing the enerery..and the modifiers prevented and preventing do not modify sound correctly..

4. energy prevented from being dissipated as a result of--is awakward
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Can you elaborate the difference in meaning between b and c.
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Hey sks,
lets break the entire sentence into clauses.
1) Sound can travel through water for enormous distances.
2) Sound is prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperatures and densities.

In your explanation you have stated that energy prevented itself ......
IMO subject is SOUND.
that's why I have been asking for the differences in the meanings of B and C.
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Skm,
Its not necessary that the verb-ed modifies the word preceding it.
that's why I told you in my earlier post. The subject is sound.
For your concept, when the subject is performing the action then we use verb-Ing and use active voice BUT when the same subject is used as the object upon which the action is performed, then we use verb-ed and passive voice.
I will really advise you to reply me back at this thread when you have read this post. You did the same earlier, forcing me to repeat my question several times.
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Initially I also fell for E. However, the correct answer is C.

To make the meaning clear, read C as:
Sound can travel through water for enormous distances - its acoustic energy prevented from dissipating by boundaries in the ocean created by water layers of different temperatures and densities.

Here it is clear that "Boundaries in ocean" prevent Sound's acoustic energy from getting dissipated.

In E (incorrect answer), the sentence implies that the "Sound" itself prevents its acoustic energy from dissipating by using boundaries in the ocean.

Hope this helps.

IMO, B is (a) wordy and (b) has no real meaning.

B implies that Sound is somehow "being prevented" from dissipating its acoustic energy - by boundaries in ocean.

At first I thought it is B, but after I read the explanation from skmskm I realized that I'm wrong.
The correct answer is C.
Tough one.
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This question bugged me, too, so here is the result of my search and hopefully the answer to your question about meaning
https://e-gmat.com/blogs/?p=413