E , why not D?

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race2mba: Junior | Next Rank: 30 Posts; Posts: 17; Joined: Thu Nov 15, 2012 8:53 am; Thanked: 1 times

by race2mba » Mon Jul 29, 2013 3:22 am

In parts of South America, vitamin-A deficiency is a serious health problem, especially among children. In one region, agriculturists hope to improve nutrition by encouraging farmers to plant a new variety of sweet potato called SPK004 that is rich in betacarotene, which the body converts into vitamin A. The plan has good chances of success, since sweet potato is a staple of the region's diet and agriculture, and the varieties currently grown contain little beta-carotene. Which of the following, if true, most strongly supports the prediction that the plan will succeed?
A. There are other vegetables currently grown in the region that contain more beta-carotene than the currently cultivated varieties of sweet potato do.
B. The flesh of SPK004 differs from that of the currently cultivated sweet potatoes in colors and textures, so traditional foods would look somewhat different when prepared from SPK004.
C. For successful cultivation of SPK004, a soil significantly richer in nitrogen is needed than is needed for the varieties of sweet potato currently cultivated in the region.
D. There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.
E. The currently cultivated varieties of sweet potato contain no important nutrients that SPK004 lacks.

OA is E, but why not D? Could some one explain this?

Source: Beat The GMAT — Critical Reasoning | Mon Jul 29, 2013 3:22 am

macattack: Senior | Next Rank: 100 Posts; Posts: 90; Joined: Wed Jun 26, 2013 10:55 pmFollowed by: 1 member; Thanked: 11 times

by macattack » Mon Jul 29, 2013 4:04 am

Problem: Vitamin A deficiency is a serious health problem.
Solution: Plant SPK004 rich in beta-carotene. (Beta-carotene is transformed into vitamine A once digested)
Assumption made: The SPK004 does not lack any important nutrients that the current variety of sweet potatoes has.

In the above passage we are analyzing whether the new variety of sweet potatoes is a viable substitute for the already cultivated ones. We are not arguing that it is the best solution.

D. There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is. (Irrelevant, even if there was other varieties of sweet potatoes richer in beta-carotene the SPK004 would still be a viable substitute to the currently cultivated ones. (It is richer, not the richest)

E. The currently cultivated varieties of sweet potato contain no important nutrients that SPK004 lacks. This addresses addresses the assumption made above, strengthening the argument.

P.S. In most CR questions, an assumption is made. In this case the assumption was implicit, you might not have caught it when reading the passage.

I hope this helped!

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by [email protected] » Mon Jul 29, 2013 10:41 pm

Hi race2mba,

Here is some additional insight regarding questions that involve a "plan." For a plan to work, it must solve the existing problem AND not create any new problems.

In this prompt, the plan is to replace one type of sweet potato (that doesn't have enough Vitamin A) with another sweet potato (which does have enough Vitamin A). We would have to assume that the newer sweet potato solves the existing problem AND doesn't create any new ones. To support the idea that the plan will work, we need to find an answer that says that this is the case.

Answer D doesn't give us the assurance that we need. Answer E does.

GMAT assassins aren't born, they're made,
Rich

Contact Rich at [email protected]

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