Nonverbal messages cannot contradict the verbal message

When an audience hears a message that is so threatening that they quit listening, the speaker has created what?

A. Co-orientation B. Defense avoidance C. Value fear D. Attitude appeal

Which of the following techniques measures participants on a variable that is thought to have an influence on the dependent variable as a means of creating comparable groups?

a. randomization b. matching c. probability sampling d. double-blind