Researchers have found that a ____________ degree of fear in a message makes it more effective, particularly when it is combined with ____________.

A) maximum; information about how to prevent the fearful consequences
B) minimum; threats
C) moderate; threats
D) moderate; information about how to prevent the fearful consequences

Moderate level of fear in a message combined with information on how to prevent the potentially feared consequence is the most effective way to enhance the persuasiveness of the message. This is because a moderate level of fear triggers a sense of vulnerability, and information on how to prevent the feared consequence provides a sense of control to the recipient of the message, increasing their perceived ability to take action. Therefore, option D is the best choice.