My oppinon I think its C.I might be wrong but that might make the most since.
Answer: D
Explanation:
Brown v Board of Education was a landmark case generally viewed as the end of segregation in schools
John f kennedy signed the declaration of independence and made them free
Yoko Ono belongs to this movement of artist, composers, and designers that really popularized the Zen philosophical practice of posing riddles, they were known as Koans, and to lead the students to the enlightenment and the movement was called Fluxus.
The principle of checks and balances refers to the system, in the American federal system, wherein each branch of government has responsibilities and obligations as it relates to the other branches of government.
The President, for one, is able to veto legislation from the Legislative Branch but a balance on that check is that the Legislative branch may override the Executive branch's veto.
