What Does the Term "Vertical Mosaic" Mean

What does the term "vertical mosaic" mean?

A) Canadian politics and society are based on an egalitarian system in which all cultures have equal opportunity and equal representation.
B) Canada's multicultural society is structured hierarchically so that certain cultures are predominant in politics and business.
C) Affirmative action has resulted in women, Indigenous people, and members of visible minority communities moving up the ladders of the corporate and political worlds.
D) While interest groups are prevalent throughout Canada, most concentrate their efforts on the federal level in Ottawa.