Answer:
A. Glass ceiling
Step-by-step explanation:
The glass ceiling is a metaphor which is used to refer to artificial barrier that prevent women from promoting to managerial and executive levels in an organization.
Glass ceiling is used to describe problem of gender inequality females face in an organization dominated by males when trying to be promoted to a higher position.
Women are usually discriminated upon in an organization when aspiring for higher positions. This was what contributed to the Ava not been promoted even though she is more hardworking and deserving than Michael.