Explanation

Since the information given by astrologers can never be conclusively proven or falsified, Sergei can’t know whether it’s true; thus, a word that means something like trickery or deception would make sense in the blank. Both vindication and authentication are nearly the opposite of what you’re looking for, so eliminate choices (C) and (D).

Neither censure, which means criticism, nor vexation, which means anger, is supported by the sentence, so eliminate choices (A) and (F). Both chicanery and wile can mean trickery, so choices (B) and (E) give you appropriate, equivalent sentences.