Sandra finds out that a rumor about her is making the rounds in the office $$ she supposedly had a rift with her manager over her performance review and is now planning to quit the company. Though completely untrue, she sets out to find the person who started the rumor. She confronts several of her colleagues regarding this and everyone tells her that they heard it from Sheela, her boss's secretary$.$ This is an example of a $\_\_\_\_\_\_\_\_.$