When Robert asked his class, "How many of you just don't have enough time to do all the things you want to do in a day?" as his speech introductory device, almost everyone in the audience raised their hands. This audience reaction is

a. an indication of verbal responsiveness.
b. an inappropriate crossing of the lines between speaker and listener.
c. restless movement, which indicated to Robert that he'd better get on with his speech.
d. an indication of nonverbal responsiveness.

d