Soil quality is one of the most important factors affecting the growth

Option B is wrong because it is stating which is not part of the question (it is irrelevant). Since the question asks, we need to evaluate the claim that planting dynamic accumulators would help farmers increase crop production?

But option B is stating that " Are there solutions other than planting dynamic accumulators that would be more effective at increasing the farmers’ crop production?"

We dont need the solution other than planting dynamic accumulators. We need to evaluate whether dynamic accumulators would indeed help farmers increase crop production.

KAPLAN OFFICIAL EXPLANATION:

STEP 1: IDENTIFY THE QUESTION TYPE
The question asks for something that would “most useful in evaluating” a claim, making this an Evaluation question. It’s useful to notice that the claim being evaluated is in the question stem itself, not in the stimulus. The claim is that dynamic accumulators would help increase crop production.

STEP 2: UNTANGLE THE STIMULUS
According to the author, successful crop growth depends on having good soil, which is a consistent concern for farmers. The author offers a solution: dynamic accumulators (plants that gather nutrients). As evidence that this would help, the author cites reports of increased plant growth in places with dynamic accumulators.

STEP 3: PREDICT THE ANSWER
The reports seem to offer some support for using dynamic accumulators. Unfortunately, the reports merely mention “plants” without indicating what kinds of plants are being grown. The claim in question is concerned specifically with farmers’ crops. If the reports are based solely on plants that farmers don’t grow, then the reports may not be representative of what would happen with crops. The correct answer should question whether or not the reports adequately represent what would happen to farmers’ crops.

STEP 4: EVALUATE THE CHOICES
(D) is correct. If none of the reports involve crops used by farmers, then the reports are irrelevant and provide no support for the claim in question. However, if such crops are examined in the reports, then that information does support the claim. (A) is irrelevant. While perhaps a source of concern for some farmers, costs do not impact whether the plants would help or not. (B) is irrelevant. Whether or not better solutions exist does not have a bearing on whether dynamic accumulators could help. (C) is irrelevant. Comfrey is just one example of a potential dynamic accumulator. The claim is not about comfrey, specifically. (E) is irrelevant. The only benefit that matters here is improving soil conditions. As long as that happens, then it doesn’t matter whether or not there are any other benefits.