Arthur Sullivan is a very enthusiastic salesperson. However, when he calls on customers, he usually leans on their desks and rearranges items on their desks to make room for his sales materials. Sullivan's sales manager needs to tell Sullivan that he is perceived as a(n):
A. space threat.
B. interloper.
C. territorial assailant.
D. territorial intruder.
E. trespasser.
Answer: A. space threat.