ExplanationThe blank describes the role played by the kind of evidence that would justify a decision to continue the investigation, so a word that means something like important would make sense. Both negligible and marginal are nearly the opposite of what you’re looking for, so eliminate choices (B) and (F). Choices (D) and (E) give roughly synonymous meanings as well, but nothing in the sentence supports the description of the role as dishonest.
Both paramount and salient can mean important, so choices (A) and (C) give you appropriate, equivalent sentences.
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