Critical Reasoning

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 clubs 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 someone who is exercising is already more than the muscle cells 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
Could you please explain how ?

utkalnayak wrote: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 clubs 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 someone who is exercising is already more than the muscle cells 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
Could you please explain how ?

The goal of the product is to increase the amount of oxygen absorbed by the muscles. The part the boldfaced portion plays in the original version is to support the argument that the product is useless by showing that using the product will not increase the amount of oxygen absorbed. So, in looking at the answer choices we need to find one that does something that similarly supports the argument by showing that the product will not work.

A) This is irrelevant. The water could still be of use and this does not indicate that the product does not work.

B) This is also irrelevant. The point of the argument is not that there are not other ways to increase absorption of oxygen. The point is that the product is useless because it will not do this.

C) This serves the purpose of the portion in boldface. In drinking water, one does not put the water or any oxygen contained in the water into one's lungs. So the oxygen in the water will not get into the bloodstream and therefore will not be available to muscles. So the product will do nothing to increase oxygen absorption by muscles, and this supports the argument that the product is useless.

D) This is irrelevant. The argument is about dealing with one limiting factor, and the ability of a product to do that.

E) The point of the boldfaced portion is not water loss. Yes, water is discussed in the argument, but the point of the boldfaced portion is to support the argument by showing that the product does not increase the oxygen absorbed by muscles.

So the only one that is relevant and that provides a reason why the product does not work is C.