SiddharthGulati98I guess you meant E.
Anyways I will share the reasoning for C and E?
The key to solve all CR questions is to focus on "Question Stem"
Question Stem - The prediction that the plan will succeed? Now lets be clear what's the goal and plan
Goal - To improve nutrition
Plan - Encouraging farmers to plant a new variety of sweet potato (MOST STRONGLY SUPPORT THIS PLAN)
Author's reasoning - Because sweet potato is a staple of the region’s diet and agriculture, and the varieties currently grown contain little beta-carotene.
(C) There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.
This option states that sweet potato is good compared with other when it comes to beta-carotene. This option states some good things about new variety. But acc. to question stem, we need to strengthen "whether the plan to encourage farmers to plant a new variety of sweet potato". So this option has no impact on the success of the plan.
When we compare both A and C, both says good things about SPK004 but A focuses on the prediction that farmers will plant the SPK004 because no extra effort needed to plant this new variety and C focuses only on good things about SPK004.
(E) There are other vegetables currently grown in the region that contain more beta-carotene than the currently cultivated varieties of sweet potato do.
We need to make an assumption that farmers are more likely to plant other varieties already present with high beta-carotene content than SPK004. What if the condition is not favourable to plant these other varieties frequently. We don't know if the other vegetables are also a staple food. Overall my belief in the plan to achieve its goal decreases.
Also a lot of assumptions not supported by passage or logic is not preferred in CR
Even if I consider your reasoning, then plan is likely to fail. So the statement WEAKENS the argument. The question stem states to "most strongly supports the prediction"
If there are other varieties already present with high beta-carotene content, then the plan to cultivate SPK004 might fail, right? Since it already has a contender that with similar beta-carotene content that is already in circulation
SiddharthGulati98
Why is C incorrect? If there are other varieties already present with high beta-carotene content, then the plan to cultivate SPK004 might fail, right? Since it already has a contender that with similar beta-carotene content that is already in circulation