Which best explains why the supreme court’s decision in plessy v. ferguson was unconstitutional?

The rule is obviously unconstitutional. Segregation by race is contrary to the phrase “All men are created equal” in the U.S Declaration of Independence and U.S Constitution. Well, the Plessy v. Ferguson just upended that, which decided that segregation laws are okay as long as there were equal in quality. The Brown v. Board of Education stated that separate educational facilities are inherently unequal,  almost effectively nulling the racist rule.

Its c i just took the test