Answer: The Peter Principle
Explanation: The Peter Principle was developed by a Canadian sociologist Dr Laurence J. Peters in 1968 . He also authored a book he titled "The Peter Principle".
"In a Hierarchy, every employee tends to rise to his level of incompetence" - The Peter Principle
The principle explains that as long as employees are competent in their respective roles, they will continue to get promoted until they get promoted to a position where they do not have the required skills and therefore become incompetent.
They can only get further promotion if they acquire skills that match their current role and become competent enough to get to the next level.
Here Mary Ann has been working for 15 years and it is likely that she got promoted a couple of times within her first 10 years.
But for the past 5 years her promotion applications have been declined because she hasn't become competent enough in her current role to get promoted.
She will only be granted an interview when her skills match her current role.