This is a strengthen question. You need to find a choice that strengthen the conclusion.
Conclusion is that the plan to grow SPK004 will be a success as Potato is a staple food.
Now Option D says that SPK004 is the richest source of betacrotene than any other potato. does this really strengthen the conclusion ? - a little, however note that conclusion is more about whether the plan to grow will be a success note how much Betacretone can you get. Premise already states that SPK004 is rich in betacreatone and whether it is the richest source does not matter.
Option - E -> removes the doubt that can weaken the conclusion i.e. eating SPK004 does not cause deficiency of some other kind. So, in a sense strengthens the conclusion.
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