Final answer:
The Peter Principle explains that employees in a hierarchy tend to be promoted until they reach a level where they are no longer competent, emphasizing the need for ongoing training.
Step-by-step explanation:
The Peter Principle in an organization is best described by the statement: In a hierarchy, employees tend to rise to their level of incompetence if they don't keep up training. This concept articulates that as individuals in an organization are promoted, they eventually reach a position where they are no longer competent, as each new role requires different skills and abilities. They will continue to be promoted until they reach a role in which they do not excel, and there they will remain. This principle illustrates a potential flaw in the structure of organizations and highlights the importance of continuous learning and development for career progression.