how did the ruling in plessy v. ferguson affect the legalities of segregation?\nit set \separate but equal\…

Brief Explanations:

In the Plessy v. Ferguson case, the Supreme Court ruled that racial segregation laws did not violate the U.S. Constitution as long as the facilities for each race were equal. This established the "separate but equal" doctrine. The other options are incorrect: desegregation legislation (like Brown v. Board of Education) came later; the "separate but equal" ruling assumed separation could be equal (which was later disproven); and there's no basis for it discouraging protests.

Answer:

It set "separate but equal" as a legal precedent.