pranayeekarmakar
HI
GMATNinja,
Could you please explain why E is wrong. I had tough time eliminatig it. is it beacuse of the word "intended to"?
The author thinks that removing trees along the banks of the Colorado River is a great idea, because it will result in more water being available for farmers' crops.
We have to
weaken this argument. In other words, we have to cast doubt on the idea that removing the trees will result in more water for the farmers.
With that in mind, take another look at (E):
Quote:
(E) The distribution of water allocations for irrigation is intended to prevent farms father upstream from using water needed by farms father downstream.
Hmm. This just tells us about who is allowed to use water from the river. It gives no insight at all into how removing the trees will impact the amount of water available to use for irrigation. Will removing the trees be great for farmers, as the author argues, or will it actually have a negative impact on the amount of water available? (E) doesn't help us answer that question at all.
So, (E) doesn't weaken the author's argument. Eliminate (E).
Compare that to (A):
Quote:
(A) The trees along the river’s banks shelter it from the sun and wind, thereby greatly reducing the amount of water lost through evaporation.
(A) tells us that the trees actually
increase the amount of water in the river. So, removing the trees might not be such a great idea -- sure, the farmers won't have to share the water with the trees, as the author says in the passage. However, the farmers might end up worse off if they cut down the trees, because now a bunch of water will evaporate from the river and be unavailable to use for crop irrigation.
(A) gives us a reason to doubt that cutting down the trees will result in more water for crops, so (A) is the correct answer.
I hope that helps!