That would be choice C. the index fossils.
I hope this helps you! :)
Answer:
Isolationism has been a recurrent theme in U.S. history. The term is most often applied to the political atmosphere in the U.S. in the 1930s. The policy or doctrine of isolating one's country from the affairs of other nations by declining to enter into alliances, foreign economic commitments, international agreements, etc., seeking to devote the entire efforts of one's country to its own advancement and remain at peace by avoiding foreign entanglements and responsibilities.
The best option from the list would be that this case "<span>declared that segregated schools were inherently separate and unequal," since it officially overturned Plessy vs. Ferguson, which said the opposite. </span>
