Final answer:
The case where the Supreme Court ruled that the 'separate but equal' doctrine’s requirement for equality had not been met was Brown v. Board of Education. This decision stated that segregated schools were inherently unequal, thereby overturning Plessy v. Ferguson and marking a major victory in the civil rights movement. The correct option is B.
Step-by-step explanation:
The Supreme Court ruled that the requirement of "equality" in the separate but equal doctrine had not been met in the case Brown v. Board of Education. This seminal decision in 1954 overturned the earlier Plessy v. Ferguson decision, which had established the separate but equal doctrine allowing racial segregation in schools and other public facilities.
The Brown v. Board of Education case was a unanimous decision that state laws establishing separate public schools for black and white students were inherently unequal and thus unconstitutional, directly challenging the idea that segregation could ever be "equal."
The court strongly indicated that separate educational facilities are inherently unequal, undermining the doctrine of separate but equal and marking a pivotal point in the civil rights movement. The decision emphasized that the only solution to removing the sense of inferiority fostered by segregation was the integration of public schools.
Hence, Option B is correct.