Tim is at his friend Michael's house. Michael says his parents won't notice if a couple of beers go missing. Tim looks down and assertively says, "No, I don't want to break their trust." When Michael insists that they won't care, Tim shrugs and looks away.

Which refusal skill is Tim forgetting to use in this situation?
A. Repeating his message as often as necessary
B. Using the word "no"
C. Using a firm tone of voice
D. Using strong nonverbal language