By building bio-gas facilities rural people’s energy needs can be

OFFICIAL EXPLANATION






• Meaning?
An energy expert believes that rural people can meet their energy needs by building bio-gas plants, which convert household organic waste such as animal dung and kitchen scraps to energy.

• Issues
→ Modifiers: The sentence begins with By building bio-gas facilities.
That phrase modifies the noun that is the subject of the next clause.
The very next thing that we should be reading about is whoever or whatever should be building bio-gas facilities.

→ Diction and style: Which of the only two logical sentences is clearer? More efficient? Less clumsy? Less amenable to misinterpretation?

• Split #1: Modifier error
When a modifier and its target noun are far from each other, we confront modifier error that is often described as a "misplaced" or "dangling modifier" (take a quick read here, which includes some good examples.

The noun (or pronoun) who would build the bio-gas facilities should immediately follow the introductory phrase.
Options A, B, and E cannot be correct.
Rural people's energy needs (option A), household organic waste (option B), and a sustainable energy expert are not supposed to build the bio-gas facility.
→ In options A and B, the noun is ridiculous. Energy needs and organic waste cannot build anything.
→ In option E, the noun after the modifier is at least a person, but from context, we know that the rural people, not the energy expert, should build the facility.

Eliminate A, B, and E.

• Split #2: Construction, style, and clarity.

Options C and D remain. They are almost identical.
No clear error exists.
But one sentence must be better than the other.

Option C is better than option D.
→ In option D, the words recommends a sustainable energy expert interrupt the explanation of how rural people can meet their energy needs (by using household waste that would be converted into energy.

Does this interruption make the sentence clearer? No. The insertion is like a hiccup.

Is there a good reason to stick those words in the middle of the sentence? (Sometimes we want to emphasize certain things, so we put their expression in an unexpected place.)
No. The energy expert is not the focus of the sentence. The way in which rural people can use household waste to meet their energy needs is the focus.

Which sentence is less amenable to misinterpretation? Clarity is key.
Option C is less amenable to misinterpretation.
In option D, we might wonder momentarily whether "by using household waste" modifies the energy expert or the rural people.
Option C does not contain the same possibility of confusion.

These details may seem trivial.
They are not: "rhetorical effectiveness" really is a thing, and GMAC wants you to understand that option C's structure and construction create an uninterrupted messaging force that option D's structure does not.
Eliminate D.

The answer is C.


COMMENTS

DarkKnight800 , welcome to SC Butler.

karnavora1 , I am glad to "see" you—it's been a little while.

Of course, I am always glad to see everyone.
People who actively engage typically enhance their confidence, which often leads to a better GMAT score.

These answers are very good.
Keep up the hard work.