A new test for AIDS has proved helpful in eliminating blood

Question

A new test for AIDS has proved helpful  in eliminating blood, contaminated with the virus, from the nation's blood supply .

(A) in eliminating blood, contaminated with the virus, from the nation's blood supply

(B) in eliminating blood from the nation's blood supply that is contaminated with the virus

(C) in eliminating from the nation's blood supply blood that is contaminated with the virus

(D) to eliminate blood that is contaminated with the virus from the nation's blood supply

(E) to eliminate blood from the nation's blood supply that is contaminated with the virus

https://www.nytimes.com/1985/08/01/world/blood-supply-called-free-of-aids.html

A new test has apparently succeeded  in screening AIDS-tainted blood from the nation's supply of blood for transfusions , according to studies reported today at a meeting at the National Institutes of Health.

The test, which was licensed last spring, ''seems to be extremely valuable in screening out''  blood contaminated with the virus  that causes acquired immune deficiency syndrome, said Dr. Harry M. Meyer, an official of the Food and Drug Administration. The test ''picks up essentially every potentially infectious unit'' of contaminated blood, he said.

GMATNinja · Accepted Answer

Seeing lots of good explanations here already! But also a little bit of disagreement.

I don't see anything wrong here grammatically. Some test-takers like to skip ahead, eliminate anything with definite grammar errors, and then circle back to choices such as (A) that don't have any obvious mechanical errors -- and that's not a bad approach at all!

But whenever you get to (A), the problem is that the modifier tweaks the meaning of the sentence. It sounds like the test eliminates all blood from the nation's blood supply, and the modifier inside the commas ("contaminated with the virus") is presented as extra, non-essential information that just describes the blood. And that doesn't make sense: the test will be helpful in eliminating  only  the contaminated blood, not all of the blood. (A) is gone.

This one has a much clearer modifier error. The phrase "that is contaminated with the virus" modifies the noun it "touches": "the nation's blood supply." And that doesn't make sense, either, since we can't really say that the entire blood supply is contaminated. Eliminate (B).

Wow, this sounds like hot garbage. I used to manage a team of writers, and if any of them had written this, I would have wondered if they were drunk or something. I don't think anybody would ever actually say this sentence in real life. It sounds terrible.

But your ear is not your friend on the GMAT! The important thing is that I don't see any grammatical errors or any meaning errors. "That" jumps out at me, but it's used well here: the blood is contaminated with the virus, not the entire supply. I guess we'll have to keep this piece of hot garbage -- it's not wrong. And we're always looking for four wrong answers, not one right answer. Since it has no clear mistakes, let's keep (C).

(D) doesn't make logical sense, either. Strictly and literally, the sentence seems to be saying that the virus came from the nation's blood supply. That doesn't work. Eliminate (D).

Same error as (B): the phrase beginning with "that" modifies the nation's blood supply, and that doesn't make sense. (E) is gone, too.

So (C) wins. In "real life", it's a lousy sentence, in my opinion. But the GMAT doesn't care: the other four answer choices have clear meaning errors, so we're stuck with crappy answer choice (C).

AliciaSierra · Answer

My OA is C.

(A) in eliminating blood,  contaminated with the virus , from the nation's blood supply----In option A "contaminated with the virus" is non essential modifier but when we see whole sentence then "contaminated with the virus" has to be essential modifier. Because statement conveys that test is helpful in eliminating contaminated blood not any blood.

(B) in eliminating blood from the nation's  blood supply that is contaminated  with the virus---"that" here modifies nation's blood supply. "Blood Supply" that is contaminated. It should be Blood that is contaminated.

(C)  in eliminating from the nation's blood supply blood that is contaminated with the virus -- Correct. "Blood that is contaminated with virus" gives intended meaning.

(D) to eliminate blood that is contaminated with the  virus from the nation's blood supply ---virus from the nation's blood supply . Wrong

(E) to eliminate blood from the nation's  blood supply that is contaminated  with the virus---blood supply that is contaminated..wrong

shkusira · Answer

A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

o in eliminating blood, contaminated with the virus, from the nation's blood supply
 Correct 
o in eliminating blood from the nation's blood supply that is contaminated with the virus
 Makes it seem that nation's bloody supply is contaminated with the virus 
o in eliminating from the nation's blood supply blood that is contaminated with the virus
 Was confused about this one, but I think A does a better job is not repeating the word blood. Cant see anything wrong otherwise 
o to eliminate blood that is contaminated with the virus from the nation's blood supply
 The virus is not from the nation's blood supply! 
o to eliminate blood from the nation's blood supply that is contaminated with the virus
 Makes it seem that nation's bloody supply is contaminated with the virus

Thus I shall go for A

pleonasm · Answer

I guess it's C.

o in eliminating blood, contaminated with the virus, from the nation's blood supply
three clauses that are totally independent.
o in eliminating blood from the nation's blood supply that is contaminated with the virus
Makes it seem that nation's bloody supply is contaminated with the virus
o in eliminating from the nation's blood supply blood that is contaminated with the virus
the use of 'that' clearly says that the blood is contaminated with the virus and not the blood supply - correct
o to eliminate blood that is contaminated with the virus from the nation's blood supply
to eliminate is wrong usage
o to eliminate blood from the nation's blood supply that is contaminated with the virus
to eliminate is wrong usage

-pradeep

x2suresh · Answer

In A.. "contaminated with the virus" --> not essential..phrase. if you remove this and read the sentence..
It doesn't make sense.

C --> that clearly introduces essential clause..

C is the best

manikanth2304 · Answer

Meaning of the sentence: A test has proved eliminating the blood from the nations blood supply which is contaminated with virus

Splitting the sentence

A new test for AIDS has proved helpful in eliminating blood, contaminated with the virus, from the nation's blood supply.

Here the subject is A new test for Aids
Verb is has proved

clearly it is a modifier error

my question is why Choice B is incorrect

in eliminating blood from the nations blood supply that is contaminated with the virus

The above sentence is clearly modifying the blood why still it is not correct.

Please help me

Thanks
Mani

egmat · Answer

Hi Mani, You have understood the meaning correct. Your breaking of the sentence is also correct. So let's see what is the problem with Choice B: Choice B - in eliminating blood from the nation's blood supply that is contaminated with the virus: Incorrect. In this choice, "that" modifies the immediate preceding noun entity "nation's blood supply". This is so because the preceding prepositional phrase "from the nation's blood supply" does not modify the noun "blood" that preceeds it. This prepositional phrase actually modifies action denoted by the noun "eliminating". Blood has been eliminated from where? Form nation's blood supply. So we see that "from nation's blood supply" is not the part of the noun "blood" and hence does not form a noun phrase in which case "that" may refer to "blood" - the head of the assumed noun phrase. Take a look at the construction of Choice C where "from the nation's blood supply" has been correctly place closer to "eliminating" and "that" has been placed after "blood" for correct modification. You can read the following article for more details on when can a noun modifier modify a slightly far away noun and when it cannot: noun-modifiers-can-modify-slightly-far-away-noun-135868.html Hope this helps. :-)

Thanks. Shraddha

mmagyar · Answer

This point is often overlooked in modifier analysis - I wish more test-takers would read that e-GMAT guide or pg. 238 of the Manhattan SC book and focus on the immediately preceding noun-phrase instead of just the immediately preceding noun.

A good official example of this is OG13 #126 the-use-of-lie-detectors-is-based-on-the-assumption-that-83581.html

egmat · Answer

Very rightly said @mmagyar, in fact very succinctly put " focus on the immediately preceding noun-phrase instead of just the immediately preceding noun ".

-Shraddha

honey86 · Answer

Can someone explain why A is wrong.

A new test for AIDS has proved helpful  in eliminating blood, contaminated with the virus, from the nation's blood supply.

contaminated with the virus  - this modifier can be overlooked.

Remaining sentence still makes sense. 
A new test for AIDS has proved helpful   in eliminating blood from the nation's blood supply.

prasi55 · Answer

Hi honey86,

Yes, you can remove the modifier to identify the main sentence:
A new test for AIDS has proved helpful in eliminating blood from the nation's blood supply.

But this is not logical! The test does not eliminate all the blood from the nation's blood supply; it eliminates only "contaminated" blood from the nation's blood supply. So the modifier, "contaminated with the virus" must be a restrictive modifier.

Secondly, the placement of the comma before the modifier makes the modifier convey "extra" information about "all blood":
Blood is contaminated with the virus.

This suggests that all blood is contaminated with the virus.

--Prasad

pooja3017 · Answer

A. This is the most attractive answer. Although, there is one thing wrong with this. Commas represent non-essential clauses. But contaminated with the blood is an essential clause. So this makes it wrong.
B. That should modify the noun close to it. Here, it modifies the blood supply whereas it should modify blood. 
C. This is the correct option.
D. helpful to eliminate is the wrong usage.
E. same as D.

Give a kudos, if u like the repsonse.

DmitryFarber · Answer

Responding to a pm asking why C beats D . . .

This is not one of the GMAT's better efforts. The short answer to why D is wrong is that "proved helpful to eliminate" is incorrect. However, I'm not convinced that the modifier structure of D creates any problems. We're eliminating blood from the blood supply, and D simply adds a modifier to say that this blood is contaminated with the virus. No one is going to think that the virus is "from the nation's blood supply."

C is awkward and ugly, but it isn't grammatically incorrect. Taking out some of the modifiers, we get a bare-bones structure of "The test has proven helpful in eliminating blood that is contaminated." Adding "from the nation's blood supply" in that position makes the sentence hard to read, but it still works. Similarly, we might say "He removed from the final draft all references to tax reform." It's fine to say "from the final draft" at the end instead, but it isn't required. However, I would only use a modifier that way if it added clarity to the sentence. It doesn't here, so I think the GMAT is doing an uncharacteristically poor job here of balancing rules with readability.

warriorguy · Answer

Hi  DmitryFarber ,

Can you please elaborate as to why "proved helpful to eliminate"? Is it because we intend to highlight the result not the purpose?

DmitryFarber · Answer

warriorguy  No, we just don't use the infinitive in this way. "In eliminating" is idiomatically correct. We would only use "helpful to eliminate" in a construction like this:

It would be helpful to eliminate the contaminated blood.

Notice that here we use "it" as a placeholder subject. What would be helpful? Eliminating the contaminated blood. Notice that "to eliminate" is not a modifier here; it actually provides the content for the subject. In this way, it's similar to "It was nice to meet you." What was nice? Meeting you.

warriorguy · Answer

To shows purpose. It proved helpful in eliminating something. So intention was not to eliminate.

Based on that - D and E can be eliminated.

Non-restrictive modifier in A changes the meaning of the sentence.

Blood that is contaminated and not nation's blood supply.

That refers to incorrect subject in B.

So Option C

Posted from my mobile device

varun4s · Answer

A new test for AIDS has proved helpful  in eliminating blood, contaminated with the virus, from the nation's blood supply.

(A) in eliminating blood, contaminated with the virus,  from the nation's blood supply   (Same as D) 
(B) in eliminating blood from the  nation's blood supply that  is contaminated with the virus  (Blood is contaminated with virus not nation's blood supply) 
(C) in eliminating from the nation's blood supply blood that is contaminated with the virus  (Correct) 
(D) to eliminate blood that is contaminated with the virus  from the nation's blood supply   (Misplaced modifier. It should have come near the verb eliminate) 
(E) to eliminate blood from the  nation's blood supply that  is contaminated with the virus  (Same as B)

Kudos please if you like my explanation!

warriorguy · Answer

Thank you  GMATNinja  for the detailed solution.

I agree with the reasons listed for D and E.

I would like to draw your attention to the phrase - helpful in and helpful to.

If other errors corrected in D, can we use "helpful to" in this case? Since we don't know if the intention of creating the new test was to eliminate the virus?

Posted from my mobile device

GMATNinja · Answer

You know that I hate idioms, warriorguy ! :lol:

I'm half-kidding. The lazy answer would be that "helpful to" is the incorrect idiom in this case, but that's not a very useful thing for me to say -- especially since "helped to" can be OK under different circumstances. To be honest, I'm struggling to find a way to explain the difference coherently, but I'll do my best. Warning: the next two paragraphs really might not be useful at all -- and they definitely aren't important!

"Helpful in" would be used to indicate purpose. The basic structure of the idiom is "X is helpful in verb-ing Y." Example: "A well-designed plan is helpful in achieving any goal". ("Helpful for" would be fine here, too.) But I think we only use "helpful to" in a funny passive structure like this one: "It is helpful to study with fellow GMAT Club members before taking the exam." Maybe somebody can correct me on this, but I think "helpful to" requires an "it is" type of construction. I don't think it makes sense to say "X is helpful to Y" or "X is helpful to accomplish Y" -- so the idiom in (D) and (E) are wrong. (If those last two paragraphs didn't help, no problem. I wouldn't worry about those specific idioms. But this next part is a little bit more important...) But here's the thing: whenever I'm unsure about an idiom, I try to avoid it entirely. Idioms are, by definition, arbitrary phrases that aren't based on generalizable rules -- and there are something like 40,000 idioms in the English language, depending on whom you ask. Sometimes, you'll know exactly which idioms are right and wrong, and that's great. But if you're not 100% sure, just see if you can find other definite, rule-based errors (as I did in my idiom-avoiding explanation above). A huge percentage of the time, you'll be able to completely dodge the idiom. There's a little bit more on the topic of idioms in last Wednesday's verbal chat transcript: https://gmatclub.com/forum/verbal-chat- ... l#p1853539. If you find it useful, give Vyshak some kudos -- I'm impressed that he managed to compile the transcript while participating actively in the conversation!

A new test for AIDS has proved helpful in eliminating blood

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GMAT Sentence Correction (SC - EA only) Questions

A new test for AIDS has proved helpful in eliminating blood

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