Which of the following is a reason for the existence of the glass ceiling in organizations?

Question $43$ options:

a$)$

Women make up less than $30$ percent of all managers, resulting in females occupying even fewer top management positions.

b$)$

There are no laws prohibiting discrimination against women.

c$)$

Some women choose to suspend or slow their career progression to have children.

d$)$

Women are not as competent as men in managerial positions.