Which logical fallacy is used in the text?
Thanks to her enduring popularity with employees, Rachel Randolph is the best-liked CEO in our company's history.

 - false causation: the assumption that because two things happened together, one caused the other
 - circular reasoning: an argument that supports a claim with the claim itself
The text argues that Rachel Randolph is well-liked, because she's popular. However, the "evidence" is just a restatement of the claim itself. This illustrates a type of logical fallacy known as circular reasoning.