Explanation

The trigger while indicates that the two parts of the sentence will disagree, and the opposition is expressed by loses and increases. Thus, the blank needs to mean effectiveness of a persuasive message. Of the choices, only cogency conveys this sense of a convincingly logical message.

Hence option E is correct!
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The trigger while indicates that the two parts of the sentence will disagree, and the opposition is expressed by loses and increases. Thus, the blank needs to mean effectiveness of a persuasive message. Of the choices, only cogency conveys this sense of a convincingly logical message.

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