Which of the following is the best example of the glass ceiling?

Richard, a White man is quickly promoted up to supervisor among hospital nursing staff.

Marco, a Hispanic man, is not hired because he does not have preexisting connections to the company.

Carla, a Black woman, is passed up for promotion despite being more qualified that her White male colleagues.

Avril, a Native American women, is repeatedly refused a transfer from human resources to marketing in her company.