how does the plessy vs. ferguson case compare to the brown v. board of education case?

a-the plessy case argued for racial harmony, while the brown case established white supremacy.

b-the plessey case was decided unanimously by the supreme court, while the brown case resulted in a 5-4 decision.

c-the plessy case separated non-whites from the rest of the society, while the brown case found this unconstitutional.

d-the plessy case took place in the 1940s, while the brown case took place in the 1960s.