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
A strong argument uses valid reasoning and logic in support of a claim. When an argument or claim introduces irrelevant information or misrepresents the issues at hand, it may be committing a logical fallacy. Logical fallacies can hurt a writer's credibility and can lead readers to draw false conclusions.
A logical fallacy may present irrelevant information:
Fallacy | Description
ad hominem | a personal attack meant to discredit one's opponent
appeal to nature | an argument that assumes the natural choice is always the best choice
bandwagon fallacy | an argument that assumes the popular choice is always the best choice
circular reasoning | an argument that supports a claim with the claim itself
guilt by association | an unfair negative association with another person or group that is intended to discredit someone or something
red herring | the use of a completely unrelated topic in support of a claim
A logical fallacy may misrepresent the issues at hand:
Fallacy | Description
false causation | the assumption that because two things happened together, one caused the other
false dichotomy | an argument that presents only two choices when more options exist
hasty generalization | a very broad claim based on very little evidence
straw man | a misrepresentation of an opponent's position that makes it easier to argue against

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.