OG - SC - #105

[GMAT 2007]

Originally developed for detecting air pollutants, a technique called proton-induced X-ray emission, which can quickly analyze the chemical elements in almost any substance without destroying it, is finding uses in medicine, archeology, and criminology.

(A) Same
(B) Originally developed for detecting air pollutants, having the ability to analyze the chemical elements in almost any substance without destroying it, a technique called proton-induced X-ray emission,
(C) A technique originally developed for detecting air pollutants, called proton-induced X-ray emission, which can quickly analyze the chemical elements in almost any substance without destroying it,
(D) A technique originally developed for detecting air pollutants, called proton-induced X-ray emission, which has the ability to analyze the chemical elements in almost any substance quickly and without destroying it,
(E) A techniuqe that was originally developed for detecting air pollutants and has the ability to analyze the chemical elements in almost any substance quickly and without destroying the substance, called proton-induced X-ray emission,


The correct answer is (A). Though, I was stuck between (A) and (B). Please help to understand the logic.

Thanks
GMAT 2007

[Guest]

To add more -

Choice (B) tempted me as the subject ('a technique') was closer to (is finding....criminology)

GMAT 2007

[StaceyKoprince]

Annoying sentence! Choice B has an opening modifier followed by a second modifier before we get to the subject. Remember that a noun modifier must touch the noun that it modifies - and the first modifier is talking about "a technique" (which is a noun), so that's problem #1, because the modifier is not next to the noun.

Then, the second modifier "having the ability..." is supposed to be talking about whatever immediately precedes it (because of the construction "having"). But the phrase that immediately precedes it doesn't actually contain the technique; the only noun it contains is "pollutants." So it sounds like the air pollutants have the ability to analyze the chemical elements etc. That doesn't make logical sense, so that's problem #2.

Finally, if you were able to rearrange all of that early stuff so that the last thing we (correctly) had was "a technique called proton-induced X-ray emission" - we wouldn't still use a comma after that last bit. Look at this:

"A technique called proton-induced X-ray emission, is finding uses in medicine..."

You either need no commas here OR "A technique, proton-induced X-ray emission, is finding..." Problem #3.

[GMAT 2007]

Thanks for the great explanantion Stacey.

GMAT 2007

[Gmat2Go]

Hi

I am still having trouble eliminating the answer choices

In B) I can see that the modifier in the beginning doesn't refer to anything
In C) the -called after the modifier, can that only modify the word immediately before it? Or can it modify the entire clause starting from the beginning of the sentence
In D) same as C
In E) is it too wordy with too many And? But its technically correct because if you take out all the verbose after that you get: A technique...., called proton induced X-ray emission, IS finding....

[StaceyKoprince]

Generally, yes, "called after" should be next to whatever I'm referring to. Same for D and E.

Also, note, if you're reading the OG explanation - they mess up here. Answers C and D say that the "which" clause "incorrectly and illogically modifies emission." That's exactly what the "which" clause should be modifying and, in fact, if you read the opening explanation to this problem, it says the "which" clause is "correctly placed next to emission."

This is not the first time I've noticed errors in their explanations - it seems sometimes that someone is cutting and pasting a bunch of stuff without going back to proofread it adequately. So just be careful there - if you notice something like this, that actually contradicts itself, you're not crazy. They just made a mistake.