One of the limiting factors of human physical performance...

[gkumar]

One of the limiting factors in human physical performance is the amount of oxygen that is absorbed by the muscles from the bloodstream. Accordingly, entrepreneurs have begun selling at gymnasiums and health club bottles of drinking water, labeled "SuperOXY," that has extra oxygen dissolved in the water. Such water would be useless in improving physical performance, however, since the amount of oxygen in the blood of people who are exercising is already more than the muscles can absorb.

Which of the following, if true, would serve the same function in the argument as the statement in boldface?

A) world-class athletes turn in record performances without such water
B) frequent physical exercise increases the body's ability to take in and use oxygen
C) the only way to get oxygen into the bloodstream so that it can be absorbed by the muscles is through the lungs
D) lack of oxygen is not the only factor limiting human physical performance
E) the water lost in exercising can be replaced with ordinary tap water

OA: C
I chose A. I ruled out D, E as they are irrelevant. I had trouble choosing between A, B, C.

How do apply POE here? Much appreciated and thanks!

[PRASUN84]

C is the best substitute.
the main function of the boldface is to highlight the fact that extra oxygen consumed through water would be useless in improving performance.

[gkumar]

That makes sense. How would you rule out A and B?

[RonPurewal]

That makes sense. How would you rule out A and B?

(a) is irrelevant. this has nothing whatsoever to do with whether the water will improve performance.
analogy: world-class athletes also turn in record performances without using steroids. this fact clearly doesn't prove that steroids are useless in improving athletic performances.

(b) is irrelevant. not only does it have nothing to do with the ways in which water is absorbed, but the "increase" is not quantified at all.
in fact, ironically, the (very indirect) effect of (b) is to contribute to the argument. if frequent exercise can increase oxygen intake, then it's possible that frequent exercisers might reach a point at which the extra oxygen in the water would start helping them.
you shouldn't think that much, though. this is a very, very, very distant relationship, and correct answers are always directly related to the passage at hand.

[taniafconca]

Would it be possible to elaborate on the explanation of C?

Thanks

[mist4u]

Ron,

Could you please explain why the other answer choices are wrong and why C is the right answer?

Also, what is the fastest way to attack this problem?

Sorry for bumping.

Thanks!!

[RonPurewal]

Would it be possible to elaborate on the explanation of C?

Thanks

the boldface needs to be something that shows that the oxygen dissolved in the drink won't help.

according to choice (c), there's no way that the oxygen in the drink could possibly go into the bloodstream (because drinks go into the stomach and not into the lungs). therefore, choice (c) shows that the drink can't be effective.

[RonPurewal]

Ron,

Could you please explain why the other answer choices are wrong and why C is the right answer?

please ask a more specific question. (also, note that choices (a), (b), and (c) have already been discussed.)

Also, what is the fastest way to attack this problem?

there's no such thing; this is a critical reasoning problem.
in fact, the very presence of this question is troubling, because it suggests that you think there's some sort of systematic approach with which you can approach these questions. critical reasoning tests your REASONING! there is NO SYSTEMATIC APPROACH to CR problems!
this is the reason why CR is such a big part of the test -- because it's impossible to approach with systematic rules and/or memorized principles.

[anwar_ghoch]

I will go ahead and throw this out:

once you've read the entire stimulus and before you start looking at the answers, try to understand the role of the statement in bold.

Here, this becomes: the product is useless because "sentence in bold"

So you'll know you are looking for a fact that would make the product useless.

If you go over the choices and the answer is still unclear, try to see if the opposite of these choices would make the product very useful.

I'm no GMAT instructor but I think this should help.

Good luck

[RonPurewal]

anwar, yes -- although what you are saying amounts to, essentially, "understand the passage and understand the question".

in other words, you are basically saying the same thing i said above -- namely, there's no way around the "understanding" part. so, in other words, there is no "fastest method".

[josesav7]

Hi Ron,

I still don't get why B would be wrong. Can you explain again please?

Thank you!!

[jlucero]

Here's my rephrase:

People have been selling water with oxygen, but the product is useless because X.

X = there's already more oxygen in the blood than muscles can absorb.

Note that B doesn't fit in here, because it has nothing to do with the water itself. The water isn't useless because there are other ways to absorb more oxygen (B). It is useless though because we don't absorb oxygen into our bloodstream through the substances we drink (C).

[josesav7]

Ok got ya.

Thanks Joe!

[tim]

:)

[NarenS469]

Hello Instructors,

Since the question is asking for the same function. So the boldface part is weakening so we need to find a answer choice that weakens.
Only answer choice C weakens.

Is my above understanding correct?

Thanks for the help

Naren